overlooked by casual students of history since it occurred so clo

American Civil War and is overshadowed by the latter's sheer 

scope. Yet, the Mexican War was instrumental in shaping the geog

boundaries of the United States. At the conclusion of this conflict, 

had added some one million square miles ofterritory, including w

are the states of Texas, Arizona, New Mexico, and California, a

portions of Colorado, Wyoming, Utah, and Nevada. This newly 

land also became a battleground between advocates for the expa

slavery and those who fought to prevent its spread. These secti

political differences ripped the fabric of the union of states and e

contributed to the start of the American Civil War, just thirteen ye

In addition, the Mexican War was a proving ground for a generatio

Army leaders who as junior officers in Mexico learned the trade o

latter applied those lessons to the Civil War. 

The Mexican War lasted some twenty-six months from 

engagement through the withdrawal of American troops. Fighting to

over thousands of miles, from northern Mexico to Mexico City, an

New Mexico and California. During the conflict, the US. Army wo

of decisive conventional battles, all of which highlighted the valu

Military Academy graduates who time and again paved the way for A

victories. The Mexican War still has much to teach us about projecti

conducting operations in hostile territory with a small force that is 

by the local population, urban combat, the difficulties of occupation

courage and perseverance of individual soldiers. The following ess

of eight planned in this series to provide an accessible and readable 

of the US. Army's role and achievements in the conflict. 

This brochure was prepared in the US. Army Center of Militar

by Stephen A. Carney. I hope that this absorbing account, with 

further readings, will stimulate further study and reflection. A com

of the Center of Military History'S available works is included on the 

online catalog: http://www.army.millcmh-pglcatalog/Brochure.htm

JOHN S. BROW

Chief of Military 
battles, captured nearly half of Mexico

s territory, and nearly dou

the territories of the United States. Initially, three US. Army fo

operating independently, accomplished remarkable feats during 

conflict. One force- under Brig. Gen. Zachary Taylor- repelled in

Mexican attacks at Palo Alto and Resaca de la Palma, north of the 

Grande. Subsequently, Taylor's force crossed the river and advanced 

northern Mexico, successfully assaulted the fortified town of Monte

and- although heavily outnumbered---defeated Mexico's Army o

North at Buena Vista. 

Concurrently, Col. (later Brig. Gen.) Stephen W Kearny l

hardened force of dragoons on an epic march of some 1,000 m

from Fort Leavenworth, Kansas, across mountains and deserts to 

California coast. Along the way, Kearny captured Santa Fe in wh

now New Mexico and, with the help of the US. Navy and rebell

American immigrants, secured major portions of California. 

Maj. Gen. Winfield Scott directed the third and decisive camp

of the war. Scott's army made a successful amphibious landing f

the Gulf of Mexico at the port of Veracruz, which was captured 

a twenty-day siege. Scott then led his army into the interior of Me

with victories at Cerro Gordo, Contreras, Churubusco, Molino del 

and Chapultepec, ending the campaign and ultimately the war with 

seizure of Mexico City. 

The conflict added approximately one million square mile

land to the United States, including the important deep-water por

coastal California, and it gave the Regular Army invaluable experi

in conventional operations. Yet, the Mexican War consisted of m

than a series of conventional engagements, and no formal armistice 

reached until long after the capture of Mexico City. Rather, the A

had to conduct a "rolling occupation," thereby serving as administra

over the captured territory as the Army's frontline units continue

pursue conventional Mexican forces. 

Incidentally, by definition, "Territory is considered occupied wh

is actually placed under the authority of the hostile army. The occupa

extends only to the territory where such authority has been establi

and can be exercised" (as defined in US. Army Field Manual 27-10 

3 
fighting the French. Army commanders also used the Mexic

rancheros to describe guerrillas. In the current study, the terms gu

and irregulars are used interchangeably. 

Both the occupation and the insurgency reflected 

sociopolitical realities of Mexico. Indeed, the country's deep an

violent racial, ethnic, and social divisions further complicated the 

the occupying forces. Regional variations between northern and 

Mexico, differences between the composition of Zachary Tay

Winfield Scott's armies and the threats they faced, and- not lea

great difference in policies pursued by the two commanders me

the U.S. Army conducted not one but two very different occupa

Mexico during 1846-48. 

Strategic Setting 

Numerous factors affect the nature and structure of occup

a military mission. The strategic and long-term goals of any o

will shape the occupation policy. This policy should work tow

anticipated end state, which can run the spectrum from annex

the restoration of independence. 

An occupying force faces several essential duties and the po

of collateral missions. Primary responsibilities include enforc

terms of the instrument ending conventional hostilities, pr

occupation forces, and providing law and order for the local pop

Collateral missions may include external defense, humanitaria

and-in some cases- nation-building, which can be the creatio

entirely new political and economic framework. Economic con

demographics, culture, and political developments all come in

and affect occupation policy. 

Mexico s Political and Social Situation at the Onset of Ho

Race and ethnicity greatly affected the history and deve

of Mexico. The descendants of native American Indians, w

4 
gppg 

economic, and racial lines, the criollos themselves were split be

conservative and liberal factions. Conservatives advocated ins

a strong centralized government, having Catholicism as the o

state religion, and limiting voting rights to the privileged few. Li

proposed granting additional powers to Mexico's states, def

religious toleration, and supported the expansion of voting righ

complicate the political scene, the liberals further subdivided them

into purist and moderate factions, each with different agendas

result, the government in Mexico City remained in a seemingly co

state of disarray that contributed to economic stagnation and an 

growing national debt. 

At the onset of the conflict with the United States, the M

government was, in theory, a representative democracy. The Const

of 1824 had created a federal system modeled on the U.S. Consti

The Mexican federal government was composed of three bra

an executive branch with a president and vice president; a legi

branch, or general congress, comprising two houses- a senat

house of representatives; and a judicial branch with a supreme 

and local circuit courts. 

In theory, the executive and legislative officials were e

through popular vote, but, in reality, only a small fraction of Me

population actually had the right to vote. In 1846, for example, les

I percent of Mexico City's population of some 200,000 met the pr

requirement necessary to vote. Even smaller portions of the popu

in outlying regions were able to vote. The ruling elite refused to e

suffrage to the remainder of the population and cautiously gu

its power and land holdings, which further alienated the Indian

mestizos. As a result, rebellions were common in Mexico. In 

for example, a revolt against the central government led by Gen

Alvarez soon turned into an Indian insurrection that spread a sw

destruction across 60,000 square miles of southwestern Mexico ce

on Acapulco. Although the Mexican Army mercilessly repressed 

outbreaks, underlying tensions seethed close to the surface as th

flared along the Rio Grande in May 1846. 

5 
PAt. 

o 

F 

A N 

SCOTT'S CAMPAIGN 

ADVANCE TO MEXICO CITY 

1846-1847 

x Engagement. Date Indicated 

U.S. Advance, Date Indicated 

Disputed Territory 

Miles 

400 

I 

MazatlanO 

/' 
T E X A S 

Austin ~ 

~ -- 0 San Jacinto 

/ / san An:onio .,/ 

'v. ( -"GOliad <9v('I5I J 

"-TAYLOR 1846 

o Victoria 

epee 

847 

" 

federal authority in Mexico City, but poli

instability and the distance between the ca

and many of the states enabled the provi

governments to enjoy a wide degree of autono

As a result, U.S. forces conducted much of 

negotiations with state and local governm

early in the war and had no real opportunity to 

with the central government until Scott laun

his campaign against Mexico City. In sum

country's governing bodies were unprepare

deal with either internal or external crises. 

American Objectives 

In 1845, Mexico's borders included more 

one-third of the North American continent, 

a population of slightly more than seven mi

people. North of the Rio Grande, Mex

holdings extended from the western borde

Texas and the Arkansas River in the east to 

Pacific Ocean in the west (Map 1). The hold

included more than one million square m

of land in what today are the states of Ariz

California, Colorado, Nevada, New Mex

Utah, and Wyoming. The geography of 

sparsely populated territory included portion

the jagged Rocky Mountains and Sierra Nev

Churubusco 

20 Aug 1847 

\...,.- the craggy Intermountain region, and the rug

Coast Range. In addition, stretches of lar

uninhabited desert contrasted with potent

valuable agricultural assets such as Califor

Central Valley. 

Those territories attracted the int

interest of many Americans, including Presi

7 
President James K. Polk (Library of Congress) 

James K. Polk and his administration, which had several clearly 

goals at the onset of the Mexican War. Polk wanted to settle the d

southern boundary between Texas and Mexico. Ever since w

independence from Mexico in 1836, the Republic of Texas had 

that the Rio Grande constituted the border separating it from M

Mexico, however, set the line some 150 miles north at the hi

between the Nueces River and the Rio Grande. When the 

States accepted Texas's application for statehood in December 

inherited the Texan claim. 

The United States also coveted Mexico's lands north of 

Grande to support its rapidly growing population of approx

eleven million by 1840. Looking westward to expand, the nation j

8 
q, 

g

had offered several times between 1842 and 1845 to purchase 

regions from Mexico. Mexico City refused all overtures bec

Mexican popular opinion insisted that the government preserve a

the territory that the nation had wrested from Spain. 

When the war officially began on 8 May 1846, President Polk 

a clear set of objectives for the U.S. Army. Secretary of War Willia

Marcy, writing for the president, ordered General Taylor's force of s

4,000 Regulars-or just under half of the entire U.S. Army- to sei

much territory in northeastern Mexico as possible. Meanwhile, M

sent Kearny's force through New Mexico and into California 

instructions to cut those regions off from the central government in 

off Mexico City. Polk and Marcy believed that the Mexican govern

would not resist an offer to purchase the territory ifU.S. military fo

already controlled it. 

Us. Army Organization 

Organized along European lines, the standing U.S. Army, design

the Regular Army, contained specialized corps of infantry, cav

artillery, and engineers. At the outbreak of the conflict, it numbered 

7,365 soldiers. In compliance with its missions of guarding the fro

and defending the nation's coastline, the Army had scattered its un

small posts manned by units of company size or less across the ea

seaboard and through the interior frontier. Because entire regim

rarely assembled, the force seldom practiced large-unit tactics. 

The core of the Army consisted of its eight infantry regiments, w

consisted of ten companies each. On paper, each company posse

fifty-five men, but at the onset of the war most averaged only th

five. Brigades consisted of an ad hoc collection of multiple regim

and divisions contained several brigades. Those larger formations 

temporary wartime organizations. 

Infantrymen in the American Army enlisted for five years 

received an average pay of $7 per month. Offering low wages and h

discipline, the service attracted the poorly educated and those with 

opportunities in civilian life. In 1845, 42 percent of the Army cons

9 
y jy g y

such highly mobile troops was evident throughout the conflict. 

The Army's artillery arm was more robust. It contained a mix

6-pound field artillery, as well as 12-, 18-, and 24-pound coastal 

weapons. Howitzers firing shells of 12-,24-, and 32-pound weigh

to the Army's arsenal. In Mexico, the Army would use primari

artillery against guerrilla forces. At full strength, American lig

artillery companies had three two-gun sections and came with 

number of horses to transport the guns, ammunition, and most 

crew. Some "flying" companies had all of their troops mounted. 

The U.S. Army also fielded a small number of highly 

engineers who served in either the Corps of Engineers or the 

of Topographical Engineers. Members of the former special

bridge and fortification construction. The latter created maps, su

battlefield terrain, and built civil engineering projects such as ro

canals. 

Soldiers from the Ordnance, Subsistence, and Quarte

Departments provided logistical support. The Ordnance Dep

supplied firearms and ammunition, while the Subsistence Dep

secured bulk food items, such as barrels of flour, salt pork, an

beef. Both operated in the rear along the Army's lines of commun

The Quartermasters had the greatest responsibility. They s

troops with all equipment other than weapons, such as uniforms, 

saddles, and tents; they also arranged transportation and o

construction projects; and, during the Mexican War, they crea

ran a series of advanced supply depots close to field operating 

that ensured a steady flow of provisions and equipment to the 

Although its long supply trains and depots sometimes became 

for Mexican irregulars and bandits, the Quartermaster Dep

provided the Army with one of the most advanced logistical 

operations in the world. 

In times of emergency, the United States called for volunteers 

in state-raised regiments to augment its small professional force. 

of volunteers was first established in the 1792 Militia Act. Vo

were compelled to serve wherever the War Department require

10 
p

g

organized into companies, battalions, and regiments. Regiments e

their own officers, although governors sometimes selected fiel

staff grade officers. The president appointed all volunteer generals

were then confirmed by Congress. After the regiments were orga

they "mustered" into federal service and came under War Departm

control. They were not, however, governed by the 1806 Articles o

the basis for the American military justice system, a situation tha

them much more autonomy than the Regular Army enjoyed. Durin

Mexican War, some 73 ,260 volunteers enlisted, although fewer 

30,000 actually served in Mexico. 

The U.S. forces' reliance on volunteer soldiers complicated m

Because volunteers were taken directly from civilian life and qu

thrown into a rigid hierarchal system, many responded poorly 

regimentation of military life. At their worst, they resented supe

disobeyed orders, balked against the undemocratic nature of m

life, and proved difficult to control. They rarely understood and gen

ignored basic camp sanitation, and they were generally unaccust

to the harsh life faced by soldiers in the field. Not surprisingly

experienced much higher death rates from disease and exposure 

the Regulars. The officers of those regiments often held their 

by virtue of political appointment or through election by those 

became their subordinates. This system offered no assurance that 

who initially commanded possessed the ability or the training to 

One senior Army officer concluded: "The whole volunteer s

is wholly indebted for all its reputation to the regular army w

which the [illegible] body of volunteers in Mexico would have 

an undisciplined mob, incapable of acting in concert, while they w

have incensed the people of Mexico by their depredations upon pe

of property." 

Swept by "war fever," the men who initially rushed to join Ta

army in northern Mexico exemplified the worst characteristics 

lot. As a group, the early volunteers were vehement racists, 

exponents of Manifest Destiny, and eager to fight and kill Mexic

any Mexicans. They had little patience with the hardships of 

11 
and proved less unruly. In addition, commanders gradually foun

to control and occupy their new soldiers, which lessened their 

effect on the Mexican citizenry. During the final months of the 

most of the volunteer troops conducted themselves with grea

restraint in camp and proved quite effective on the battlefield. 

Throughout the war, both Taylor and Scott also relied hea

special companies of mounted volunteers: the Texas Rangers, wh

as the eyes and ears of the Army by conducting crucial reconna

collecting intelligence, and carrying messages through Mexica

They also launched raids against specific targets, especially g

encampments. Technically state militia and not mustered into 

service, the Texans voluntarily agreed to serve in Mexico

depredations on the Mexican citizenry were often excessive, h

and their behavior, along with that of other volunteers, did m

spark local Mexican resistance. 

us. Army Counterinsurgency Doctrine 

The U.S. Army had no official doctrine covering occup

counterinsurgency operations in 1846. In the absence of for

manuals, its professional soldiers instead passed on informal 

that was based on traditions and experiences from one gener

officers to the next through personal writings and conversation

of it applied directly to the situation the troops encountered du

Mexican War. For example, American forces had no experienc

control of foreign territory other than a winter's occupation of p

of Quebec Province during the American Revolution and som

forays into Canada during the War of 1812. In 1813 during a th

sojourn in York, the Canadian capital, American troops had loo

then set fire to large portions of the town and its harbor. This u

precedent, the product of poor discipline and heavy losses, po

more relevance in 1846 than some American commanders c

acknowledge. 

The volunteers' actions during the various Indian Wa

bequeathed a mixed heritage. The Second Seminole War (18

12 
Texas Ranger (Library of Congress) 

which pitted the Army against some 1,500 Seminole and Af

American warriors in the Florida Everglades provided a partic

relevant example. The Seminoles used their knowledge of the n

impenetrable Florida swamps to conduct ambushes whenever pos

In response, the Army shunned conventional tactics, such as try

coordinate several converging columns over virtually impassible te

and adopted an unconventional approach. Commanders establis

series of heavily garrisoned posts to protect white settlements a

limit the Seminoles' ability to move with impunity. They also 

active patrolling from those posts to find and destroy Indian village

crops, as well as Indian war parties whenever possible. The tactics 

both brutal and effective. Generals Taylor and Scott would apply s

measures during the occupation of Mexico. 

13 
Spanish military detachments and the long supply trains that eq

them. 

Expert horsemen, Mexican guerrillas usually fought while m

Heavily armed with rifles, pistols, lances, sabers, and dagger

showed particular skill with lassos and preferred to rope their 

and drag them to death when possible. They mastered the local 

and had the ability to use complex networks of paths, trai

roads to strike the unwary and then to disappear into the coun

Fortunately for the Americans, many guerrillas doubled as thiev

failed to differentiate among their victims and often attacke

own countrymen for personal gain. Although the general pop

sometimes supported them, many Mexicans tired of their attac

occasionally worked with the Americans to stop them. 

The Mexicans also employed irregular cavalry units, often 

from local ranchers and commanded by regular troops. In 

military terms, those forces would be designated as partisan f

"Partisan" describes organized guerrilla bands fighting under M

regular officers or officially sanctioned by the Mexican gover

The term "partisan" did not enter the U.S. Army lexicon until 

General Order No. 100, which differentiated between armed pr

guerrillas, and partisans. The term is appropriate in the curren

however, because there was considerable partisan activity dur

conflict, especially in central Mexico. 

Although not officially part of the Mexican Army, the p

cavalry often operated under close supervision of the regula

Although Generals Antonio Canales and Jose Urrea were th

known partisan leaders in northern Mexico, the Mexican gove

devoted considerable attention to raising partisan forces to har

U.S. Army on its march toward the capital. Aware that Scot

supply line and the attitude of the civilians along this route w

to the success or failure of the American campaign, the leader

Mexico City decided to disrupt convoys carrying ammunition an

supplies and to otherwise harass American forces. On 28 Apri

just ten days after the Mexican defeat at Cerro Gordo, a newly i

14 
Mexican guerrilla (Colecci6n Banco Nacional de Mexico) 

president of Mexico and adviser to Antonio Lopez de Santa An

the enigmatic Mexican strongman- Pedro Maria Anaya, ordere

creation of a series of volunteer Light Corps to attack Scott's lin

communications. Seventy-two Mexicans, most wealthy and twenty

of them military officers on active service, received permission to 

the units. Brig. Gen. Jose Mariano Salas, a close friend of Santa A

played a prominent role in the effort. Terming the units "Guerrill

Vengeance," Salas recruited volunteers by vowing that he would "a

and destroy the invaders in every manner imaginable," under the sl

"war without pity, unto death." 

The units in the corps were designed to target supply 

replacement convoys, small parties of American troops, and stragg

15 
Operations 

Because of Mexico's immense size and population, the US

in reality occupied only a small area that encompassed key pop

centers along Mexico's lines of communication. This arrangem

necessitated by the fact that the US. Army never maintained mo

30,000 troops in Mexico during the entire war. The Polk admini

expected this handful of soldiers- less than 0.4 percent of th

population of Mexico-to pacify some 7 million Mexicans. 

the Mexican War, the United States occupied two regions of 

proper. Taylor and Scott occupied more than a thousand squar

of northern and central Mexico, respectively. Brig. Gen. Step

Kearny's troops did occupy a third area north of the Rio Grande

today is New Mexico and California- but large numbers of Am

had already filtered into those regions and the United States 

intend to return either one to Mexican control. In addition, the a

Mexico occupied by Kearny's troops contained only 90,465 inh

as of the 1842 census. Of those, a significant number were US. 

Such a small number of civilians possessed far less poten

troubling a US force than did the millions of their countrymen wh

to the south. In addition, the area was already closely tied to the 

States economically through well-established trade routes. The s

in those areas, therefore, was markedly dissimilar to what con

Taylor and Scott in Mexico proper, which had little indigenous 

for annexation. Because there were no significant guerrilla 

against Kearny, and he quickly integrated New Mexico and Ca

into the United States, this study will not explore his occupation

Unique circumstances and personalities produced wildly d

types of occupation in Mexico. Zachary Taylor, known to his tr

"Old Rough and Ready" for his casual demeanor and willing

share his soldiers' hardships, often neglected troop discipline. W

Scott, nicknamed "Old Fuss and Feathers" for his attention to de

fondness for pompous uniforms, insisted on strict adherence 

and regulations. 

16 
Camargo (Map 2). The Saltillo to Camargo line became one of th

important supply and communications routes in the north. By war

Taylor's forces controlled a region extending as far as Victoria 

southeast and Parras to the west. 

Taylor quickly achieved the purely military objectives that th

administration assigned him. Within four months, he won de

battles at Palo Alto, Resaca de la Palma, and Monterrey, thereby f

Mexico's Army of the North to withdraw some 400 miles south 

the Rio Grande to San Luis Potosi. Taylor's occupation of no

Mexico, however, did not compel Mexico's government to sell 

the territories sought by the United States as President Polk had h

In fact, the situation in northern Mexico deteriorated rapidly in res

to the local depredations of the volunteer troops. 

Until June 1846, Taylor's army consisted of Regular Army troop

enjoyed some popularity with the citizenry. Matamoros's citizens h

American force in higher esteem than they did the Mexican Army, 

had abandoned all of its wounded when it retreated from the tow

U.S. Army had immediately set up hospitals to minister to the si

wounded and had provided for the basic needs of the townspeople

The dynamic changed when volunteers moved into the are

immediately began raiding the local farms. As the boredom of ga

duty began to set in, plundering, personal assaults, rape, and 

crimes against Mexicans quickly multiplied. During the first 

after the volunteers arrived, some twenty murders occurred. 

Initially, Taylor seemed uninterested in devising diversio

occupy his men and failed to stop the attacks. As thefts, assaults, 

murders, and other crimes perpetrated by the volunteers mo

and Taylor failed to discipline his men, ordinary Mexican c

began to have serious reservations about the American inv

Taylor's lackadaisical approach to discipline produced an effect 

unanticipated by the Polk administration, many of whose mem

particularly pro-expansionists such as Secretary of the Treasury R

1. Walker, believed that Mexicans would welcome the Ame

as liberators. Instead, public opinion turned against the Ame

17 
20 40 60 80 100 

I 

Salinas o Monterrey /",o . 20-23 Sap 46 V Mann 

--'" 

\ 

" o ' Montemorelos 

and began to create a climate for guerrilla bands to form in th

Mexicans from all social backgrounds took up arms. Some o

were trained soldiers; others were average citizens bent upon ret

against the Americans because of attacks against family mem

18 
Zachary Tay lor (Library of Congress) 

friends. Criminals joined in, and bandits and highwaymen bega

flourish, looking for easy prey. 

As Taylor's force moved up the Rio Grande and its line

communications extended, irregulars began to capture and 

stragglers, the sick, and the wounded who fell behind on long marc

The local populace increasingly appeared more than willing to sup

and shield the guerrillas. The volunteers' racism, anti-Catholic

and violence provided all the motive that locals needed to oppose 

19 
py p

some 100 civilians, including many who had been killed by Co

C. Hays' 1st Texas Mounted Volunteers. A few weeks later, app

in retaliation, Mexicans killed a lone soldier from a Texas re

just outside Monterrey. Rangers under Capt. Mabry B. "M

Gray responded by killing some twenty-four unarmed Mexica

The event galvanized much of the population against Taylor's A

Occupation. 

The boredom of occupation duty led to additional w

violence. During November 1846, for example, a detachment f

1 st Kentucky regiment shot a young Mexican boy, apparently fo

and Taylor again failed to bring any of the guilty soldiers to just

The most concerted and organized irregular campaign in n

Mexico began in February 1847, during the initial phase of th

for Buena Vista, and it lasted nearly a month. As Taylor repo

his troops around Saltillo to contest Santa Anna's advance, the M

commander sent a detachment of partisan cavalry under Genera

to sever the Monterrey- Camargo road, Taylor's line of commun

to the Gulf coast. Urrea's cavalry joined forces with General C

force of partisan irregulars, which had been active in the regio

the onset of hostilities the previous spring. Urrea was determ

strike isolated garrisons and Taylor's lightly defended supply 

As Taylor's lines of communications had lengthened and becom

difficult to defend, his supply convoys had become attractive tar

guerrillas, a vulnerability that he failed to recognize. 

On 22 February, Urrea's mounted guerrillas attacked a wag

containing some 110 wagons and 300 pack mules just five miles 

the undefended hamlet of Ramos, which was some seventy-fiv

northeast of Monterrey. While a portion of the attackers surroun

train's guards posted at the front of the column, others went 

for the wagoneers. During the short skirmish, Urrea's men 

approximately fifty teamsters, drove off the survivors, forced the 

to surrender, and captured most of the supplies. 

The partisan commander next gathered up the undamaged 

and mules and moved on to attack the American garrison at 

20 
way, they picked up some twentyfive survivors of the initial R

Massacre." Arriving in Marin soon after Irvin left, Morgan ordere

men to continue south after midnight on the morning of 26 Febr

when a number of Urrea's lancers attacked them just outside the t

When Morgan sent a messenger to Monterrey for reinforcement

courier came upon Irvin's colwnn marching southward. In resp

Irvin and 150 of his men turned back to join forces with Morgan

the reinforced column reached Monterrey without further inciden

the end, Morgan and Irvin estimated they had killed some fifty part

while suffering five wounded and one killed. Urrea's force, how

effectively closed the route between the Rio Grande and Monterre

Defens e of supply convoy (Library of Congress) 

21 
parked the train and organized his men into a defensive perimet

The initial guerrilla assault failed to break through Gidding

but succeeded in destroying about forty wagons and killing sev

American civilian teamsters and soldiers. Strengthened by a 

column from Camargo the following day, the Giddings column r

Camargo without further incident. 

Next, Taylor sent Col. Humphrey Marshall's 1st Kentucky c

regiment northward from Monterrey to locate the guerrilla 

Marshall soon reported that Urrea was again near Marin. In res

Taylor organized a brigade of dragoons, Capt. Braxton Bragg's b

and Col. Jefferson Davis's 1st Mississippi Rifles and personally 

to Marin. Joining Marshall early on the morning of 16 March 

Taylor sent a portion of the force to guard a supply train movi

of Camargo while the rest of the force pursued Urrea. Althou

Americans failed to engage the guerrilla leader, their presence i

large numbers made further organized partisan operations a

U.S. supply routes in the region impossible. Subsequently, 

retired southward toward San Luis Potosi, allowing Taylor to 

his supply lines to the Rio Grande. To prevent similar situation

recurring, Taylor continued to send mixed armed groups wit

convoy. He also positioned additional units at various garrisons 

his lines of communication and sent "Mustang" Gray's Texas R

to operate in the area. The Rangers hoped either to find and eli

the guerrillas or to terrorize the local people to such an exte

they would stop supporting the irregulars. Such measures wer

partially successful. 

On 4 April 1847, General Canales called on all Mexicans 

up arms against the Americans and threatened to execute as traito

who refused. Guerrilla attacks increased through the summer an

the fall of 1847. A large partisan force raided the supply depot a

some 180 miles northwest of Matamoros, on 7 September, ca

off some $26,000 worth of supplies. A hastily organized pa

dragoons and civilian teamsters caught the irregulars, who were 

considerably by their plunder, allowing the Americans to reclaim 

supplies after killing some fifteen of the enemy. 

22 
line and killed Martinez, whom Taylor had labeled 

the most acti

the guerrilla chiefs on this line." 

A few days after Martinez's death, Texas cavalrymen found 

raided a guerrilla camp near Ramos, about fifty miles to the north 

west of Camargo, killing two more irregulars and capturing a 

number of horses and mules, as well as arms and other equipment. T

two victories helped curb the violence that had been common alon

Rio Grande since the previous May. 

American commanders finally supplemented tactical measures 

more enlightened policies to reduce violence against civilians. 

Maj. Gen. John E. Wool, the military governor of Saltillo, insti

strict curfews, moved garrisons out of city centers, set up road b

to keep soldiers away from populated areas, and threatened to disch

any unit whose members indiscriminately slaughtered Mexican live

or plundered from the locals. Although conditions improved somew

violent crimes against Mexican citizens continued. In fact, Taylor him

announced that he would hold local governments responsible for U. S. A

goods destroyed in their jurisdiction and would lay "heavy contribu

.. . upon the inhabitants," a punitive policy that was effective. 

Taylor and Wool also decided to organize Mexican police forces 

a lightly armed constabulary that was responsible for particular reg

Raised from local citizens, the units were to "ferret out and brin

the nearest American military post for punishment ... " any guerrill

their supporters. Although the units' actions against Comanche In

raiders along the Rio Grande enhanced their local popularity, the 

had little effect on guerrilla operations. 

Frustrated in September 1847, Taylor granted General Woo

authority to try any Mexicans "who commit murder and other g

offences on the persons or property ... " of the American Arm

Occupation. Based on a similar order that General Scott had is

in central Mexico, the measure governed military tribunals in the 

under the general's jurisdiction and essentially placed the region u

military law. 

In December, Secretary of War Marcy reinforced the harsh meas

by directing that local authorities turn guerrillas over to the Americ

23 
John E. Wool (National Portrait Gallery, Smithsonian Institu

If they failed, then the Army had the authority to hold entir

responsible for any violence that took place in surrounding ar

Mexicans who provided material support to guerrillas would 

pay fines but also forfeit all personal possessions. The measures 

Within a few months, Wool collected more than $8,000 in fines

24 
in cold blood.

 As a result, anyone who pays tribute to Canales 

any other person in command of bandits, or guerrilla parties ... w

punished with utmost severity." 

Wool's final report in 1848 credited the decrease in guerrilla a

to three basic policies. First, holding local leaders personally respo

for guerrilla activity in their jurisdictions curbed high-level suppo

the irregulars. Second, making localities financially accountab

U.S. government property lost in attacks made local citizens he

to harbor attackers. Finally, Wool contended, the use of native 

forces helped forge bonds between the Army of Occupation an

local populace and allowed the Americans to collect intelligenc

they would never have found otherwise. Others, however, place 

emphasis on the large number of troops on security duty, their off

operations against the partisans, and the measures taken to at 

separate the volunteer troops from the civilian population. 

Scott s Occupation of Central Mexico 

While Taylor struggled with Mexican resistance in the north 

the battle at Buena Vista, Scott launched his central Mexico cam

(Map 3). In February 1847, leading elements of his invasion 

seized the Gulfport town of Tampico for use as a staging point. S

occupation effort began at that point and ended with the Am

withdrawal in July 1848. By then, Scott's area of control ext

some 280 miles from the port of Veracruz to Mexico City and stra

Mexico's National Highway- roughly the same route that the Sp

conquistadores had followed on their march to the Aztec capital in 

One of the few paved routes in Mexico, the road allowed heavy w

to move up and down its length with ease. 

From the initial planning stage in October 1846, Scott's cam

had objectives far different from those of Taylor's northern mi

By the time Scott had outlined his plans for the invasion of c

Mexico, Taylor's presence in northern Mexico had clearly fai

compel the Mexicans to cede California or any of the other ter

coveted by U.S. leaders. As a result, Scott intended to carry the w

25 
Piedra

( 

/~ :Jf

:f~ ~

1 

J 

SCOTT'S CAMPAIGN 

ADVANCE TO MEXICO CITY 

7 March -14 September 1847 

x 

-

- Engagement, Date Indicated 

U,S, Army Movement 

Mexican Withdrawa l 

Mites 

30 

I 

I 

I 

the heart of Mexico, capturing the nation's capitaL This, he and th

administration reasoned, would force Mexico to accept US, term

The strategy, although well conceived and necessary to brin

war to a successful conclusion, was fraught with danger. Operat

Mexico's most populated territories, Scott's army would rarely nu

more than 10,000 troops at the leading edge of his advance duri

entire campaign. For much of the time, Santa Anna's army outnum

Scott's by nearly three to one. The Americans would be hard-pres

deal with the Mexican military, let alone any civil uprisings or pa

attacks similar to those besetting Taylor. Scott understood fro

beginning that he would have to secure the loyalty and respect 

local citizens or fail in his mission, 

26 
: ..... , 

<'I't t ~::~~~ --- ~"--- ". 1~~ ,,;tii' 

Scott owned an extensive personal library including work

the history of Napoleon's occupation of Spain from 1808 to 181

particular, Sir William Francis Patrick Napier's three-volume Histo

the Peninsular War guided his planning for his future campaign. M

French experience for insights, he was struck by the rancorous con

of the French troops toward the Spanish population and the failu

harsh French occupational measures to quash the growing uprising t

As provocations multiplied on both sides, the fighting escalated o

control. The French responded by setting fire to entire villages, sho

civilians en masse, destroying churches, and even executing pr

The locals retaliated in kind. Although the Spanish irregulars ope

without any centralized command and control structure, indiv

27 
pppy 

p

proper model for operating in a potentially hostile land. 

In light of his studies, Scott wrote his General Order N

commonly known as the Martial Law Order, even before he l

Mexico. Issued at Tampico on 19 February 1847, it made rape, m

assault, robbery, desecration of churches, disruption of religious se

and destruction of private property court-martial offenses not only 

Mexicans and all US. Army soldiers but also for all American ci

in Mexico. Scott closed the gap by making everyone- whether s

civilian, or Mexican citizen- subject to the US. Army's jurispru

All accused offenders would be tried before a court made up of o

appointed by the commanding general. 

Scott administered his tribunals, or commissions, in much th

way as modern courts-martial. He appointed one Regular Army 

to preside over the proceedings as judge advocate of the court

other officers, usually from volunteer regiments, made up th

Another officer prosecuted the case, while an officer from the acc

unit served as a defender. A Regular officer defended civilian

American and Mexican. Commissions heard one case or multiple 

over an extended period, sometimes lasting for weeks. The tribun

the authority to determine innocence or guilt and to levy punis

which included the lash, hard labor in ball and chain, impriso

branding, and even death. The commanding general- and som

the War Department-had to approve the most severe sentences. 

The system was hardly foolproof. In one notorious case, a vo

from the 1st Pennsylvania Regiment stood trial for theft. The a

solider had used the stolen goods, including a watch and a gold cr

to ensure that his compatriots would support his alibi. He had also 

the defending officer to prevent him from exposing the deception

end, the soldier went free. 

Scott's order closed an obvious loophole that had existed 

1806 Articles of War, which had previously prescribed the cond

US. soldiers in wartime. Because the authors of that code had 

imagined that the United States would fight a war in foreign te

they failed to extend its jurisdiction beyond America's border

28 
code of conduct. 

In reality, Scott aimed General Order No. 20 at the volun

Alarmed, both Secretary of War Marcy and Attorney General N

Clifford argued against its harsh provisions, fearing that the volu

and their families might be enraged and turn to Congress for rel

the end, however, neither man forbade issuance of the proclamati

As for the Regulars, both Scott and Taylor held them to strict sta

throughout the war. Even petty theft was punishable by thirty 

with rawhide. Indeed, many Regulars noted the injustice of volu

literally getting away with murder while they faced extremely 

punishments for comparatively minor crimes. This inequity contr

to some of the tension and animosity that existed between volunte

Regular soldiers. 

General Scott's policies underwent their first test immediatel

the surrender of Veracruz on 27 March 1847. At that time, Scott re

General Order 20, declared martial law, and arranged for the centr

distribution offood to the city's population, which had suffered s

privation during the siege. Another public proclamation stated th

U.S. Army was a friend to the Mexican people and that it wou

away with the abuses that the Mexican government had inflicted 

people. 

From this enlightened beginning, Scott's occupation cam

differed markedly from Taylor's. By insisting on strict discipline

preempted many of Taylor's problems with volunteers. When a m

commission found two soldiers guilty of stealing from a local 

for example, the Army imprisoned both in the town's dungeon. 

another commission found Isaac Kirk, a "free man of color" w

for the Army, guilty of rape and theft, the Army hanged him. 

quickly issued a proclamation on 11 April 1847 declaring th

capital punishment proved the Army would protect the Mexican p

Those examples and others like them had their effect. Scott repo

few weeks later that after the imposition of these sentences, " ..

offenses by American soldiers abated in central Mexico." 

Scott also assured merchants that the Army would protec

goods. As a result, local markets reopened for business quick

29 
population that if the Mexican people cooperated with his force

war would end more quickly and with less devastation. Such po

convinced Veracruz's inhabitants to accept American occupation 

little noticeable resistance. Life returned to normal in the tow

Scott wrote Secretary of War Marcy that the people "are beginn

be assured of protection, and to be cheerful." 

Unlike the Polk administration, Scott understood and ho

local mores. When Marcy suggested that he raze San Juan de Ulu

culturally important castle in Veracruz, for example, Scott refus

grounds that the destruction of such an important site would onl

anger and resentment. Scott knew that successful guerrilla camp

like those in Spain against the French, required an environment h

to the occupiers. He used discipline, good public relations, a

understanding of the local culture to keep that from happening. 

To win the war in the shortest possible time, Scott planned to ab

many of his resources and to march boldly into Mexico's interior to 

the country's capital in a single daring stroke. He also understood t

could accomplish the task with fewer than 10,000 frontline troop

if the Mexicans who lived along the Veracruz- Mexico City co

provided goods and food and declined to rise up en masse again

forces. Consequently, Scott insisted that his officers pay in fu

at a premium price all provisions his army gathered from Mex

He also ordered, "The people, moreover, must be conciliated, so

or well treated by every officer and man of this army, and by 

followers." Public opinion had to be favorable, or at least neutral, t

the Americans. Thus, as in Veracruz, he maintained strict disc

throughout the ensuing campaign to Mexico City and insisted on 

punishments for transgressors. When a soldier in the 8th Infantry 

a Mexican woman at Jalapa, a military tribunal ordered him h

The military similarly executed two civilian teamsters in the tow

murdering a local boy. 

Because of his astute observations and careful planning, Scot

a type of guerrilla different from the one that opposed Taylor. 

than facing an angry population such as the one supporting v

irregular forces in the north, U.S. forces in central Mexico were 

30 
q

with Scott's main force. Raising this force delayed Quitman'S dep

from the coast for several weeks. 

The number of attacks on Americans climbed steadily duri

summer and fall of 1847. The first actions focused on small 

of soldiers. In one instance on 2 May 1847, guerrillas rode dow

soldiers, "lassoed" them "around their necks and dragged on the gr

and then speared their battered bodies. Scott responded with 

Samuel Walker's mounted Texas Rangers, ruthless fighters outfitte

Colt six-shot revolvers. Walker's men engaged the guerrillas out

La Hoya and Las Vigas, two towns about seventy miles northw

Veracruz, killing some fifty Mexican irregulars. 

Travel on the National Highway, nevertheless, became increa

dangerous. In June, Lt. Col. Ethan Allen Hitchcock, Winfield 

inspector general and later his chief of intelligence, began using M

criminals liberated from prisons as couriers to slip through the gu

infested corridor to the coast. His first messenger, a convicted hi

robber named Manuel Dominguez, assured him that other pri

hostile to Santa Anna and the government would eagerly s

such missions. Believing that such a group could provide va

intelligence services, Hitchcock proposed recruiting a "Spy Com

made up entirely of Mexicans. Scott eagerly endorsed the pla

Hitchcock raised a 100-man force under Dominguez's comman

included many former prisoners. 

The company gathered information, provided messenger

acted as guides and translators. Some of its most valuable intell

came from its members who infiltrated Mexico City as "market 

from Chalco .. . selling apples, onions, etc." From those missio

spies gave Hitchcock detailed reports about the situation in th

and its defenses. Scott also instructed them to capture or kill gu

leaders whenever possible. As a result, the company captured M

Generals Antonio Gaona and Anastasio Torrejon during operation

Puebla. Overall, the Spy Company performed effectively, easily sl

undetected through Light Corps positions along the Veracruz- M

City road. Concerned, Santa Anna himself offered all of the s

31 
Samuel Walker (Library of Congress) 

"pardon for all past crimes" and "a reward adequate to any servic

may render to the Republic." 

Scott also had other sources of human intelligence. Records 

that his command spent some $26,622-or more than $520,0

2004 dollars- in payments for information-gathering efforts. O

Hitchcock paid $3,959 directly to the Spy Company as salaries. Th

32 
Ethan Allen Hitchcock (Library of Congress) 

went to informants, deserters, Mexican officers, and even one of 

Anna's servants. 

As the Americans rushed to create an intelligence apparatu

partisans made American supply trains a continual target. A co

under the command of Lt. Col. James S. McIntosh, for example

Veracruz on 4 June 1847 with nearly 700 infantrymen and approxim

33 
Located some thirty-five miles northwest of Veracruz, the 

spanned a wide valley with imposing terrain on both its sides, cre

perfect bottleneck for the convoy. Only after McIntosh and Cadw

fought a series of fierce actions against Light Corps positions 

the bridge, losing thirty-two dead and wounded, was the convo

to continue. Pushing on, it next came under assault on 21 and 2

when an estimated 700 men attacked it at La Hoya. Again, Cadw

and McIntosh's troops eventually battled their way through

Mexican Spy Company later located additional guerrillas prepa

ambush the column yet again, but Captain Walker's Rangers rush

of their garrison at Perote, a nearby town, and managed to dispe

irregulars. The column reached Scott's main force a few days la

After the heavy resistance faced by McIntosh, Scott d

to use larger and more heavily armed convoys. Brig. Gen. F

Pierce, a future president of the United States, departed Vera

early July 1847 with 2,500 troops, 100 wagons, and 700 mules

1,400 Mexican irregulars met the supply train at the National B

however, and forced Pierce to retreat to Veracruz after losing 

men. Reinforced with artillery and additional forces, Pierce eve

reached Scott's force at Puebla without further incident. 

Another column carrying much-needed supplies departed V

on 6 August 1847, guarded by some 1,000 men under Maj. F

T. Lally. Again, the irregulars attacked, and Lally lost 105 men 

fought his way through the resistance. The commander at V

sent three companies to assist, but enemy action forced even tha

column to return to Veracruz after it lost all but one supply wa

yet another fight at the National Bridge. In the end, Lally mana

push through the enemy's positions and to reach Scott's army 

days later. 

The next supply train set out from Veracruz in September 

Maj . William B. Taliaferro reported that his force faced daily 

and lost several men in each one. Even at night, Light Corps pa

harassed the Americans with heavy fire, but, in the end, Tal

broke through and reached Scott. 

34 
y

, 

also made it a punishable offense to enter the town alone. He instr

soldiers to travel in groups of six or more, to be armed at all time

to leave camp only if accompanied by a noncommissioned officer

Such orders reflected an additional threat. Men from the 

Corps continually worked their way into American garrisons at 

killing individual soldiers. In the seaport garrison at Villaher

Commodore Matthew C. Perry, US. Navy, explained that "Me

troops infiltrated the town every night to pick off Americans; thi

the kind of fighting they liked and they were good at it." Attem

prevent the attacks proved unsuccessful because "dispersing Mexi

seemed "no more effective than chasing hungry deer out of a veg

garden. They always drifted back, to take pot shots at 'gringos.'" 

Thomas Claiborne, commander of the garrison housed in the fo

Perote, reported that "the guerrillas were swarming everywhere 

vigorous leaders, so that for safety the drawbridge was drawn up 

night." 

Scott's capture of Mexico City on 14 September 1847 di

end his woes. While the Mexican regulars fled, average citizen

criminals who had been released from prisons as the Americans en

the city began using stones, muskets, and whatever other we

were available to oppose the US. Army's advance. The irregular 

combat quickly turned vicious. The US. Army responded with 

range artillery fire against any building that housed guerrillas. Alth

such tactics ended widespread resistance, the partisans instead fo

their attacks on individual and small groups of soldiers. 

Meanwhile, the Light Corps continued to restrict the flo

supplies, mail, money, and reinforcements to Scott. Shortly 

pacifying Mexico City in mid-September, Scott turned his mind 

problem posed by the increasingly bold partisans. First, he enl

the garrison at Puebla to some 2,200 men and constructed fou

posts along his line of communications at Perote, Puente Naciona

Frio, and San Juan. Completed by November, each post contained 

750 soldiers. Their commanders were required to send strong p

into the countryside to find and engage irregular forces. Finally, 

35 
Scott entering Mexico City (Library of Congress) 

decided that all convoys would travel with at least 1,300-man 

Thus, by December, he had diverted more than 4,000 soldiers, o

26 percent of the 24,500 American troops in central Mexico, to 

his supply lines. 

Scott also created a special antiguerrilla brigade and placed 

the command of Brig. Gen. Joseph Lane, a veteran of the figh

Buena Vista. Lane's combined-arms force of 1,800 men in

Walker's Rangers, as well as additional mounted units an

artillery, stressing mobility to better locate and engage Mexica

Corps units. The brigade patrolled the Mexican National Highw

attempted to gather intelligence from the local population, either t

cooperation or intimidation. Although not numerous enough to 

the entire length of the Veracruz- Mexico City corridor, the brig

succeed in carrying the war to the partisans and their supporters

Lane's brigade was most successful in an engagement with 

Light Corps unit led by Gen. Joaquin Rea on the evening of 18 O

1847 outside the town of Atlixco. Lane posted his available artil

a hill overlooking the town and initiated a 45-minute cannonade 

irregular positions. After the bombardment, he ordered his for

Atlixco. The operation destroyed a significant portion of the Ligh

force with Mexican casualties totaling 219 wounded and 319 

36 
Unfortunately, Lanes unit became most infamous for a 

engagement that followed an incident at Huamantla, a few miles 

the town of Puebla, on 9 October 1847. When Captain Walker 

Texas Rangers fell mortally wounded in the skirmish, Lane order

men to "avenge the death of the gallant Walker." Lt. William D. W

reported that, in response, the troops pillaged liquor stores and qu

became drunk. "Old women and young girls were stripped of 

clothes- and many others suffered still greater outrages." Lane 's t

murdered dozens of Mexicans, raped scores of women, and burned 

homes. For the only time, Scott's troops lost all control. Lane es

punishment in part because news that Santa Anna had stepped do

commander of the Mexican Army after the engagement at Huam

overshadowed the American rampage. 

In Washington, however, many would have applauded su

incident. Angered by the Mexican partisans' successes, the 

administration ordered Scott to destroy the Light Corps' "haunt

places of rendezvous," a directive that eventually led the U.S. 

into a scorched-earth policy. Although Scott had his doubts abou

tactics, he realized the necessity of denying the guerrillas sanctuar

thus applied "the torch" as historian Justin Smith commented 

much liberality, on suspicion, and sometimes on general principl

huts and villages; and in the end a black swath of destruction, le

in width, marked the route" from Veracruz to Mexico City. When 

extreme measures failed to stop the Light Corps' attacks, Scott i

a forceful proclamation on 12 December 1847, declaring tha

quarters will be given to known murderers or robbers whether 

guerillos or rancheros & whether serving under Mexican comm

or not. They are equally pests to unguarded Mexicans, foreigner

small parties of Americans, and ought to be exterminated." 

Once again, such measures failed to diminish the Light C

effect on Scott's line of supply. On 4 January 1848, a force of 

400 irregulars attacked a supply convoy near Santa Fe, in the st

Veracruz, and carried away 250 pack mules and goods. On 5 Jan

the irregulars attacked another convoy at Paso de Ovejas. Col. D

Miles, the convoy commander, requested reinforcements of at lea

37 
successes of the mounted Light Corps partisans cannot be deni

had a deleterious effect on the US. Army's freedom of action. 

Scott s Stabilization Campaign 

Scott's success against the regular Mexican Army had unex

consequences. Its demise eliminated one of the primary el

holding Mexican society together. Without fear of reprisal, p

across the country rose up in revolt. Between 1846 and 1848

thirty-five separate outbreaks occurred across Mexico. In each c

rebels targeted wealthy, landed elites and symbols of the nation's 

authority. A large revolt on the Yucatan peninsula in early 1848 

some 30,000 Indians against wealthy white landowners and me

living in the region. The governor of the state issued an urge

for help, saying that the peasants were waging a "war of exterm

against the white race." Here and elsewhere, the unrest took a h

in both human and economic terms. 

The state of unrest caused the US. Army two problems. Fi

revolts steadily grew in size, frequency, and violence, thereby thre

to engulf US. forces. If the peasant revolts that swept through V

targeted Scott's army, as well as the upper-class Mexicans, all c

lost. Second, without a strong central government in place, no 

treaty with Mexico would be possible and thus no legal guaran

the territorial acquisition that the United States desired. As Pr

Polk explained about Mexico, "Both politically and commercia

have the deepest interest in her [Mexico's] regeneration and pro

Indeed, it is impossible that, with any just regard to our own saf

can ever become indifferent to her fate." 

The Mexican elites recognized the necessity of reaching som

of peace accord before they could rebuild their army, the prere

ensuring their hold on power. The central government, in exil

Scott occupied the capital, thus faced a conundrum. It con

a two-front war, one with the United States and the other w

rebellion, the former gradually appearing as the lesser of two ev

38 
y 

pgg

both governments to ratify, the accord met most American de

Mexico recognized US. sovereignty in Texas, with its southern 

resting on the Rio Grande, and agreed to cede Upper Californ

New Mexico, the region that eventually became the states of A

California, Nevada, New Mexico, and Utah, as well as porti

Colorado, Nebraska, Oklahoma, and Wyomillg. In return, the 

States promised to pay Merico $15 million in gold and to 

responsibility for all outstanding claims that American citize

against Mexico. In short, the war with Mexico and the Tre

Guadalupe Hidalgo largely defined the current western borders 

United States, making a country that stretched from coast to coa

While the two nations carried out their respective ratif

processes, they concluded a truce on 6 March 1848. Tills 

overlooked document not only confirmed that all hostiliti

ceased but also included a stabilization plan to rebuild the M

government. One important part of the agreement read, "If any b

armed men be assembled in any part of the Mexican Republic 

view of committing hostilities not authorized by either governm

shall be the duty of either or both of the contracting parties to 

and disperse such body; without considering those who comp

In effect, the Umted States prorillsed to support the existing M

government against any internal rebellions, while Mexico agr

disband any guerrillas still operating against US. forces. 

The measure benefited the American Army more than the M

government, as Light Corps ullits raised and directed by the 

government almost immediately ceased troubling Scott's force

agreement accomplished what the American military could no

force of arms alone-end guerrilla attacks in the Veracruz- M

City corridor. Elsewhere, Mexican rebels of all stripes simply a

the US. rilliitary and concentrated their efforts in areas outside 

control. 

The stabilization plan also provided that the Umted States 

supply modern weapons to the Mexican government to aid 

reconstitution ofthe federal army. In the first delivery alone, the Me

39 
Brown Bess muskets. 

Finally, in an effort to stabilize the Mexican econom

Americans allowed Mexican merchants to join their convoys be

Veracruz and Mexico City and to sell their wares to the Army

corridor had long served as a key commercial route, and thus the 

presence expanded trade and provided a great, albeit temporary, 

to the region's economy. The US. Army also escorted Mexican t

who carried precious metals from the mining regions in northern M

to the Rio Grande and eventually to the Gulf coast. 

The Us. Army and the Problems a/Occupation 

Although US. forces won every conventional battle, a mul

of issues arose to threaten the occupation once it began. Log

difficulties in particular proved a major factor. The simple mov

of the materiel deep into Mexico over rough roads took signi

planning. Army Quartermasters partially alleviated their diffic

by creating a series of forward supply depots in the southern U

States along the Gulf coast and up the Rio Grande. Those d

permitted the Quartermasters to pre-position equipment and su

and to forward them far more quickly to critical points in the t

of operations. However, a general shortage of transport- wh

steamships to move supplies up the Rio Grande, wagons to tra

level areas with established roads, or pack mules to caravan th

mountainous regions- prevented many goods from reaching the t

in a timely manner. As a result, American forces had to acquire mu

their supplies directly from local Mexican sources, often by purch

them at premium prices. 

As supply lines lengthened, the effort to guard those routes be

difficult and required increased numbers of troops. Early in the co

Taylor had paid little attention to convoy security. Because o

Mexican guerrillas scored several impressive victories against l

armed supply trains and managed to carry away tons of sup

money, and mail. In the end, both Taylor and Scott were forc

40 
eventually decreased the amount of materiel lost, but their pr

never prevented the guerrillas from attacking. 

Individual couriers who moved alone to carry messag

important orders to far-flung units often fared worse. Mexican gu

and bandits consistently targeted them. In one famous in

guerrillas ambushed and killed a messenger carrying a note to 

detailing the amphibious assault on Veracruz and the shift of Am

military forces to central Mexico. The guerrillas promptly conve

letter to Santa Anna, who responded immediately by attacking T

reduced army at Buena Vista after which he planned to rapid

south and defend Veracruz against Scott. Fortunately for the Ame

Taylor's force held the field against Santa Anna at Buena Vista, in

heavy casualties, although the Mexican general managed to esca

organize an army to face Scott during the Mexico City campaign

Religion also played a crucial role in the occupation. The c

that America had a God-given Manifest Destiny served as a po

justification for the conflict. Yet, the idea itself contained stron

Catholic views that undisciplined volunteers easily acted out in M

sometimes making the Catholic Church and its property their 

Although the enlisted ranks of the Regular Army itself included 

Catholics, Protestants made up the bulk of the volunteers. In fact

officials in the Polk administration and the Army feared that such c

would lead to an all-out religious war. For example, when vol

stabled their horses inside the Shrine of San Francisco in Mon

the local population was incensed. Concerned, Polk approached 

Catholic bishops in the United States, requesting that they 

chaplains to the Army in Mexico to allay fears that the Am

intended to destroy the Catholic Church. Two priests accom

Taylor's force through mid-1847, although bandits murdered o

the second left because of ill health. 

General Scott reacted differently. Instead of assigning pri

his columns, he ordered that the troops respect all Catholic prie

church property. When one drunken soldier beat a church wo

military tribunal sentenced him to twelve lashes and hard labor i

41 
curried favor with conservative criollos by strictly prohibiting th

of any church property without his consent, allaying many fears th

Americans intended the church's destruction. Although Scott's co

calmed the Mexicans, many American volunteers, nevertheless, re

his favoritism toward the church, a policy that may have damag

postwar popularity at home. 

Analysis 

Two distinct zones of occupation were led by two di

commanders during the conflict. One was in northern Mexico 

Zachary Taylor, and the other was in central Mexico and was 

Winfield Scott. In both regions, the Army's occupation policie

successes and failures. Many shortcomings could be traced to t

of poorly disciplined volunteers serving under bad officers. In ad

the Army also discovered that its force structure, although well 

to fighting conventional battles, was often inappropriate for cond

counterinsurgency missions. 

Taylor's occupation in northern Mexico began easily en

However, he failed to institute any formal policies to keep his own 

or Mexicans who opposed the occupation in check until the la

months of the conflict. In the interim, his loose control over every

his zone of influence led to disorganization and violence, which 

not be overcome solely by harsh, oppressive measures. Indeed, 

such responses were counterproductive, fueling continued dissen

Scott, however, insisted on strict discipline and a code of co

before his troops ever set foot in Mexico and enforced such proc

throughout the campaign. His military tribunals, which held all 

troops- whether Regulars or volunteers- to the same code of co

limited senseless violence against Mexicans and created an enviro

in which the local population felt secure with the American prese

Clearly, the behavior of the American volunteers sparked 

Mexican guerrillas. Both Regulars and volunteers themselves p

to the senseless violence perpetrated by America's volunteer t

42 
Mexico. 

Because of the differences between Taylor and Scott i

occupation policies, the Mexican guerrillas in the two 

differed in many ways. In northern Mexico, highway robbers, b

and persons bent on revenge perpetrated many of the assa

individual and small groups of American soldiers. Taylor's inab

unwillingness to control his volunteers fueled those types of 

Not until relatively late in the occupation did he and Wool rein 

unruly troops. Belatedly, they created tribunals to try both soldi

Mexican citizens and took steps to impose various punitive m

aimed at destroying popular support for guerrilla fighters. 

During the Buena Vista campaign, the Americans in n

Mexico also faced structured and organized partisans. Those irr

focused their attacks on supply trains and small garrisons. I

Taylor did little to make convoy security a priority, but after gu

closed the Camargo-Monterrey supply corridor, he began to 

more and more of his frontline troops to guard duty. Eventua

presence of so many American troops guarding the supply line

it too dangerous for large groups of guerrillas to operate in the 

The mission, however, limited the ability of Taylor's forces to 

any further offensive operations. 

Scott's case differed. Individual guerrillas certainly to

opportunity to prey on lone American soldiers in central Mexi

the general's close control of his volunteers allayed many pr

in the region. For the most part, his forces faced highly org

partisans fighting under the commanders of various Light Corp

The semiconventional forces focused on disrupting Scott's l

,. communication. Responding quickly, Scott provided escorts 

American wagons moving along the Veracruz-Mexico City c

organized special brigades to hunt down irregulars, created a 

of garrisons at key points along the Mexican National Highw

endorsed the creation of the Mexican Spy Company. Again, the d

the Army's troop resources was considerable. Even with those me

however, he found it impossible to stop all the attacks. 

43 
to remain on the roads, unable to decisively engage the fast-m

guerrillas, who blended with the local population. Time and again

American forces arrived too late to catch the elusive, mounted guer

Even the few mounted US. Army regiments available enjoyed 

sporadic success. Out of frustration, some soldiers in those units 

attacked innocent Mexicans. 

Mexican responses to the occupation varied in effectivene

the north, individual guerrillas often carried out attacks to a

American atrocities without any sense of planning or strategic pu

Although the attacks created a bloody war of retribution in areas 

they occurred, they did little to challenge American authority. 

Generals Taylor and Wool brought their troops under disciplin

provided the Mexicans with a sense of security, the violence dimin

and the number of attacks decreased significantly. The no

resistance did score a significant success, however, when it used 

groups of partisans fighting under trained military leaders durin

battle of Buena Vista. Those organized forces cut Taylor's access 

vital supply line on the Rio Grande. Not until the Americans com

thousands of troops to the Camargo-Monterrey corridor were the

to compel the Mexicans to retreat. 

In the south, Light Corps units proved extremely success

disrupting Scott's otherwise nearly flawless thrust toward Mexico 

The officially sanctioned, well-led, and well-trained forces endan

all American attempts to move along the National Highway and 

a number oflirnited victories. Even as Scott devoted more attentio

troops to defeating the Light Corps, his lack of cavalry and his in

to force the irregulars into a decisive engagement frustrated his 

Yet, even with all of their successes, the Light Corps did not alt

outcome of the war. 

Lessons learned in the occupation of Mexico also had long-l

effects on America's military establishment. It most certainly pro

valuable experience for junior US. Army officers and enlisted m

experience they would find invaluable thirteen years later whe

American Civil War began. For example, young officers such as U

44 
1864, as well as later conventions. 

Although the numbers of killed and wounded in the major 

are relatively certain, it is much more difficult to calculate a

numbers of men serving, or who died of other causes, because 

keeping in the mid-1800s was imprecise at best. The statistics 

1846-47 reports by the Secretary of War, however, make it p

to approximate the figures. During the conflict, 78,718 Am

servicemen served in the theater. From the start of the conflict t

January 1848, 1,556 soldiers were killed and another 4,15

wounded during the conflict's major battles. Also, from Januar

until the final withdrawal of American personnel, the Army a

approximately 4,500 additional men from a variety of causes, in

combat, disease, and desertions. The available statistics cannot a

for the fate of some 2,800 men. This evidence strongly sugge

guerrillas and other irregular forces were responsible for many o

losses. Any concrete proof, however, will be impossible to 

Extant primary sources written by American officers tend to m

or even completely ignore irregular forces. Estimating the n

of civilians, primarily wagon teamsters, killed during the con

completely outside the realm of possibility because no agency ke

of their presence. But we do know that guerrillas killed large n

of civilians during specific time periods. In late February 1847 

partisans operating on the Carmargo- Monterrey corridor kille

65 civilian teamsters. In the end, though, disease and accidenta

proved far more deadly, killing approximately 11,550 troops. 

Neither American victories in the field, nor Taylor's mism

efforts in the north, nor Scott's well-organized occupation in th

of the country was the lone compelling reason that Mexico made 

Internal Mexican political and social discontent and fear of wide

peasant uprisings helped convince members of the nation's p

elite that further resistance threatened their survival. A comb

of twenty-two months of conflict, occupation, and civil strife 

allowed the Polk administration to achieve all of its war aims. 

45 
fg 

p

NC: University of North Carolina Press, 2002. 

--- . Levinson, Irving. Wars within Wars: Mexican Guer

Domestic Elites, and the United States of America, 1846-184

Worth, TX: Texas Christian University Press, 2005 . 

---. Smith, Justin H. The War with Mexico . New York: Macm

1919. 

- --. Winders, Richard B. Mr. Polk 's Army: The American M

Experience in the Mexican War. College Station, TX: Texas 

University Press, 1997. 

46 
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