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**U.S. Army Corps of Engineers****by Martin Reuss and Charles Hendricks**
**- The Beginnings to 1815 
- Improving the Nation's Transportation System 
- Mexican and Civil Wars 
- Responding to the Needs of a Growing Nation 
- World War I 
- Multipurpose Developement 
- Combat and Military Construction Activities 
- The Corps' Response to Natural Disasters****Former Seal of USACEShield reunites USACE (left) and Topographic (right)emblems of 1863****- Research and Development 
- Responding to New Needs 
- Military Contingencies and Humanitarian Assistance 
- Environmental Activities 
- The Changing Look in Water Resources Development 
- Conclusion
- Bibliography
- Commanders 1775 — present
**The Beginnings to 1815**
**The history of United States Army engineers can be traced back to June 16, 1775, when theContinental Congress organized an army with a chief engineer and two assistants.  ColonelRichard Gridley became General George Washington's first chief engineer.  However, it was notuntil 1779 that Congress created a separate Corps of Engineers.  Army engineers, including severalFrench officers, were instrumental in some of the hard-fought battles of the Revolutionary Warincluding Bunker Hill, Saratoga, and the final victory at Yorktown (> > >).
At the end of the Revolutionary War, the engineers mustered out of service.  In 1794, Congressorganized a Corps of Artillerists and Engineers, but it was not until 1802 that it reestablished aseparate Corps of Engineers.  The Corps' continuous existence dates from this year.  At the sametime, Congress established a new military academy at West Point, New York.  Until 1866, thesuperintendent of the academy was always an engineer officer.  The first superintendent, JonathanWilliams, also became the chief engineer of the Corps.  During the first half of the 19th century, West Point was the major and for a while, the only engineering school in the country.
From the beginning, many politicians wanted the Corps to contribute to both military constructionand works "of a civil nature." Throughout the 19th century, the Corps supervised the constructionof coastal fortifications and mapped much of the American West with the Corps of TopographicalEngineers, which enjoyed a separate existence for 25 years (1838—1863).  The Corps of Engineersalso constructed lighthouses, helped develop jetties and piers for harbors, and carefully mappedthe navigation channels.
Once reestablished, the Corps of Engineers began constructing and repairing fortifications, first inNorfolk and then in New Orleans.  The Corps' fortifications assignments proliferated during the five years of diplomatic tension that preceded the War of 1812.  The chief engineer, ColonelJonathan Williams, substantially expanded the system of fortifications protecting New YorkHarbor.  The works, which Williams and his successor Joseph Swift erected around that harborincluding the 11-pointed fort which now serves as the base of the Statute of Liberty, convincedthe commanders of the British navy to avoid attacking that strategic location during the War of1812.
 Responding to the success of its fortifications during the War of 1812, the United States soondeveloped an expanded system of modern, casemated, masonry fortifications to provide the firstline of land defense against the threat of attack from European powers.  While Congress reducedthe size of the country's infantry and artillery forces after the war, it retained the increased numberof officers that it had authorized for the Corps of Engineers in 1812.  Pleas from severalsecretaries of war for more engineers to work on fortifications led Congress to double the size ofthe Corps again in 1838.  The fortifications which the Army engineers built on the Atlantic andGulf coasts and after 1848 on the Pacific coast securely defended the nation until the second halfof the 19th century when the development of rifled artillery ended the earlier impregnability of themassive structures.

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**Improving the Nation's Transportation System**
**Although its work on fortifications was important, perhaps the greatest legacy the early Corps ofEngineers bestowed to future generations was its work on canals, rivers, and roads.  America wasa young nation, and rivers were its paths of commerce.  They provided routes from western farmsto eastern markets and for settlers seeking new homes beyond the Appalachian frontier.  The riversbeckoned and enticed, but then could treacherously destroy the dreams of unwary travelers andshippers whose boats were punctured by snags and sawyers or stranded by sandbars.  Bothcommercial development and national defense, as shown during the War of 1812, required morereliable transportation arteries.  Out of those unruly streams engineers carved navigation passagesand harbors for a growing nation. 
Still, federal assistance for "internal improvements" evolved slowly and haphazardly, the productof contentious congressional factions and an executive branch generally concerned with avoidingunconstitutional federal intrusions into state affairs.  In 1824, however, the Supreme Court ruled inGibbons v. Ogden that federal authority covered interstate commerce including riverinenavigation.  Shortly thereafter, Congress passed two important laws that, together, marked thebeginning of the Corps' continuous involvement in civil works.  The General Survey Actauthorized the president to have surveys made of routes for roads and canals "of nationalimportance, in a commercial or military point of view, or necessary for the transportation ofpublic mail." The president assigned responsibility for the surveys to the Corps of Engineers.  Thesecond act, passed a month later, appropriated $75,000 to improve navigation on the Ohio andMississippi rivers by removing sandbars, snags, and other obstacles.  Subsequently, the act wasamended to include other rivers such as the Missouri.  This work, too, was given to the Corps ofEngineers the only formally trained body of engineers in the new republic and, as part of thenation's small army, available to serve the wishes of Congress and the executive branch. 
The work was important.  At first a Board of Internal Improvements, headed by an engineerofficer, planned surveys and the development of canals, roads, and railroads.  The board, theEngineer Department, and the War Department agreed that national defense and inlandtransportation were complementary and interdependent.  This idea governed earliest activities.  Insome cases various modes of transportation were considered in relationship to each other.  Thus,an 1826 investigation considered whether it was practical to unite the Kanawha River with theJames and Roanoke rivers by canals, railroads, or both.  However, by the mid 1830s, local politicalconsiderations outweighed any overall plan in determining which projects received attention. 
Much of the work was done by the topographical engineers or "Topogs," who reported to aseparate Topographical Bureau in the Engineer Department.  In 1838, the topographical engineersbecame a separate corps and remained that way until 1863 when they were reunited with theCorps of Engineers.  As surveyors, explorers, cartographers, and construction managers, thetopographical engineers helped open the nation's interior to commercial development andsettlement. 
Congress expanded the Army engineers' workload in 1826.  New legislation, authorized thepresident to have river surveys made to clean out and deepen selected waterways and to makevarious other river and harbor improvements.  Although the 1824 act to improve the Mississippiand Ohio rivers is often called the first rivers and harbors legislation, the 1826 act was the first tocombine authorizations for both surveys and projects, thereby establishing a pattern that continuesto the present day.
An early project that reflected engineer innovation was the removal of sandbars in the Ohio River.By September 1825, topographical engineer Major Stephen H. Long, working on the Ohio Riverjust below Henderson, Kentucky, had constructed a wing dam consisting of two rows of morethan 600 wooden piles, driven to a depth of 16 feet.  He experimented with the proper angle,width, and length to achieve the greatest velocity of current.  Theory and empirical data agreedthat the increased velocity should reduce the sandbar and increase the height of the river.  Longfinally figured out an angle and length for the dam that seemed to work, and the dam served as theprototype for many others along the Ohio River.  It required no significant repair until 1872.
 Long, however, was not completely satisfied with his work.  He realized that the dam would notprevent the formation of sandbars.  From year to year, the Ohio would continue to push and carrysediment downstream, forming bars at many different points, including the dams themselves.Long's misgivings led to further innovation.  He convinced Colonel Alexander Macomb, the chiefengineer, to sponsor a contest to find a machine that could eliminate navigation obstructions.  Thewinner would receive a prize of $1,000 and, potentially of more value, a contract to open up theOhio River.  However, the winner, John Bruce, designed a boat of limited use.  Moreover, heargued with Macomb over the terms of the contract.  Long suggested someone to replace Bruce.He was Henry M. Shreve, a man known for has navigation skill on the Mississippi and Ohio riversand for his pioneering efforts to bring trade and commerce to the Mississippi Valley. 
Shreve cared little for hydraulic theory.  His attitude was to design whatever it took to get the jobdone, and he constructed a revolutionary new steam-powered snag boat.  Put into service in 1829,it became the model for steam snag boats on the Ohio, Mississippi, and elsewhere.  Shreve's boatran full steam into the snags, jarring them loose.  The limbs were then hoisted and broken apart onthe vessel's deck.  "Uncle Sam's tooth pullers," Shreve's snag boats came to be called.  They wereunlike anything known elsewhere in the world, and their impact was dramatic.  Insurance andshipping rates dropped, and the number of steamboats on the Mississippi and Ohio riversincreased significantly.  (Picture at left from Harper's Weekly, November 2, 1889, resembles snag boats of the 1840s and 1850s.)
The innovative work to clear the nation's rivers of navigation obstacles continued after the CivilWar.  In 1871, engineer Major Quincy A. Gillmore chartered a steamer and converted it forsuction dredging.  Named the Henry Burden, the converted boat was the Corps' first hydraulicdredge, and one of the first in the country.  Within three years, the government purchased anotherpropeller-driven steamer, the Woodbury, and converted it into a suction dredge to deepen theCape Fear River below Wilmington, North Carolina.  More than half a dozen hydraulic hopperdredges were constructed for the Corps just before the turn of the century. 
After the Civil War, a special Army Engineer Board concluded that a system of locks and dams onthe Ohio River was preferable either to continued dependence on wing dams and dredging or tothe construction of a system of canals to by-pass the Ohio's obstacles.  Major William E. Merrill,who was in charge of Ohio River improvements, needed to develop a system of river regulationdams that would easily allow passage of coal barges.  He concluded that the wicket dam designdeveloped by Jacques Chanoine in France in 1852 would be best, and in 1874 he formallyproposed that a series of movable dams, employing Chanoine wickets, be constructed on theOhio.  After Congress approved Merrill's plan in 1877, the Corps began constructing the DavisIsland project, just south of Pittsburgh.  Completed in seven years, the 110 x 600-foot lock and1,223-foot dam were the largest in the world at that time.  The Davis Island Lock was also one ofthe first in the country to use concrete in place of stone masonry.  The Corps' success at DavisIsland led Congress to authorize extension of the project down the Ohio.  Later, the Corpsincreased the initial 6-foot channel to 9 feet.  The project was completed in 1929 at a cost of about$125 million. 
Throughout the 19th century, engineer officers were involved in the construction, maintenance,and rehabilitation of canals and river navigation features.  They surveyed the Chesapeake and Ohioand the Muscle Shoals canal routes in the 1820s.  Several prominent Army engineers launchedtheir careers at the revived Muscle Shoals after the Civil War.  These included Major William RiceKing and Lieutenants William Louis Marshall later chief of engineers, and George W. Goethals.  Goethals designed the Riverton Lock with a low-water lift of 26 feet, the largest yet attempted inthe United States when the Muscle Shoals Canal opened in 1911.  Successes like these assuredthat engineers like Goethals would be called on again, as he was for the Panama Canal  (picture above shows work in progress). 
The Corps' canal-building efforts continued in the 20th century.  After the federal governmentpurchased the Chesapeake and Delaware Canal in 1919, the Corps' Wilmington (Delaware)District directed a reconstruction effort to deepen the channel to 12 feet and add several bridges.Traffic soon increased, and as an immediate result, demands were made to enlarge it.  The C&DShip Canal became part of an intercoastal waterway envisioned to connect existing bodies ofwater in a line roughly paralleling the coast from Boston south to Key West and then west to theRio Grande.  Today, the Corps retains responsibility for this canal and the entire intracoastalwaterway of which it is a part. 
Aside from the actual construction and maintenance of canals, locks, and other navigationfeatures, Army engineers performed important survey work.  Two important surveys were of theGreat Lakes and the Mississippi Delta.  The necessity for a good survey of the Great Lakes hadlong been recognized, for the uncharted lakes posed significant navigation hazards.  Armytopographers had surveyed some of the Great Lakes as early as 1823, but Congress did notappropriate funds for a systematic survey until 1841.  Captain William G. Williams, who had beenthe general superintendent of harbor improvements on Lake Erie, headed the survey. 
Despite the modest and belated support given to the Great Lakes survey, the subsequent yearsrevealed a rare congressional consensus that the work was, indeed, important.  From 1841 to1860, Congress appropriated a total of $640,000 for the survey; funds were provided in 10 ofthose 20 years.  The survey itself was daunting.  Some 6,000 miles of shoreline needed to besurveyed.  The surveyors determined latitude and longitude; measured the discharge of rivers intothe Great Lakes; surveyed rivers, narrows, and shoals; develop charts and maps; and markedpoints of danger.  A special iron-hulled steamer was constructed for the work.  The Corpscontinued this survey work until 1970, when many of the survey office's functions weretransferred to the newly established National Oceanic and Atmospheric Administration.  TheDetroit District of the Corps of Engineers assumed the responsibility for forecasting lake levels. 
The scientific conclusions of the Mississippi Delta survey gave it an importance in the history ofhydraulic engineering out of proportion to the funds invested in it.  In September 1850, respondingto the pleas of southern congressmen seeking federal assistance to fight the periodic disastrousflooding that struck New Orleans and other lower Mississippi River communities, Congressappropriated $50,000 for a topographical and hydrographical survey of the Mississippi Delta,including a study of the best means of securing a 20-foot navigation channel at the Mississippi'smouth. 
Topographical engineer Captain Andrew A. Humphreys initiated the survey and maintainedoverall supervision of the project, but beginning in 1857 he received the assistance of a youngengineer, Second Lieutenant Henry L. Abbot.  Abbot's field work proved so indispensable thatwhen the final report was published in 1861, Humphreys named Abbot as its coauthor.  Officiallycalled the Report Upon The Physics and Hydraulics of the Mississippi River, the survey is oftensimply referred to as the Humphreys Abbot report. 
The two Army engineers submitted a report full of new details about the lower Mississippi Basin.From just south of the junction of the Mississippi and Ohio rivers to where the Mississippi emptiesinto the Gulf of Mexico, they obtained data on river flow, channel cross sections, and generaltopographical and geological features.  After having examined some 15 different formulas andfound each lacking, they proceeded to develop their own formula to measure the flow of water inrivers, one that subsequently also proved faulty.  Most important, it failed to take into account thedegree of roughness of the slopes of a river channel.  Still, their work stimulated other hydraulicengineers, and further research led to important theoretical discoveries.  The report obtained therespect of engineers around the world. 
The conclusions of Humphreys and Abbot decidedly influenced the development of riverengineering and the evolution of the Corps of Engineers.  The authors believed that "levees only"could control flooding along the lower Mississippi.  Neither costly reservoirs nor cutoffs wereneeded.  The Corps of Engineers accepted these conclusions for nearly 60 years, not just for thelower Mississippi but for other large rivers as well.  The "levees only" policy profoundly affectedthe manner in which the United States developed its water resources.  Indeed, the influence of theHumphreys Abbot report extended past World War II, despite the fact that by then Congress hadauthorized hundreds of reservoir projects. 
In the 19th century the Corps of Engineers also constructed roads.  The most famous project wasthe Cumberland or National Road that was constructed between 1811 and 1841.  The roadextended from Cumberland, Maryland, across the Appalachian ridges of western Pennsylvania toWheeling and then across the midsections of Ohio and Indiana to Vandalia, Illinois.  The Corps'involvement on the road occurred in large part because civilian superintendents failed.  Congressauthorized the Treasury Department to build the road in 1806, but in the following years theTreasury Department was accused of inefficient, costly, and unsatisfactory progress on theproject.  In 1825, President John Quincy Adams turned the responsibility over to the WarDepartment. 
In constructing the National Road, the Corps applied the techniques developed in England byJohn McAdam, and it engaged in some innovative bridge building.  At Brownsville, Pennsylvania,Captain Richard Delafield, a future chief engineer, built the first bridge in the United States with acast-iron superstructure, an 80-foot span that remains in use today.  By 1840 engineer officers hadoverseen construction of 268 miles of macadamized surface with bridges across all but the widestrivers. 
Engineer officers also superintended railroad work after 1824.  They surveyed railroad routes and,once construction commenced, the War Department loaned engineers to various railroadcompanies.  Thus, with the permission of the chief engineer, Captain William G. McNeill enteredthe service of the Baltimore and Ohio Railroad in 1828 to supervise the surveying andconstruction of a railroad line.  In October 1829, the Baltimore and Ohio Railroad began layingtrack under the supervision of Lieutenant George W. Whistler.  By 1830 many officers were beinggranted furloughs to work on railroads, in either construction or surveying activities.  Finally, in1838, Congress passed legislation that prohibited granting leave to Army officers to allow themtemporary employment with private companies. 
In the 1850s' westward expansion generated interest in a rail link from the Mississippi to thePacific coast, and topographical engineer officers surveyed and evaluated four alternative routesfor the road, gathering a great deal of scientific information at the same time.  The Corps ofEngineers sponsored two more surveys after the Civil War in an effort to gather knowledge aboutthe American West.  One survey, led by a civilian, Clarence King, explored the 40th parallel routeacross the "Great Basin" that extended from the eastern slope of the Sierra Nevada to the westernfringes of Wyoming and Colorado, while Major George M. Wheeler led another scientificexpedition into the Southwest.  Both expeditions produced a wealth of data on the natural historyof the West.

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**Mexican and Civil Wars**
**U.S. Army engineers played significant roles in the Mexican and Civil Wars, providing bothmapping and construction services and troop leaders in theaters of operations while largelysuspending work on navigational improvements.  Engineers of all ranks gained renown for theirmilitary efforts during their service in Mexico in 1846—48.  Chief Engineer Joseph Totten directedthe successful siege of the port city of Veracruz, from which General Winfield Scott launched hisdecisive assault on the interior of the country.  Captain William Williams, who had directed theGreat Lakes survey, served as chief topographical engineer for General Zachary Taylor until hisdeath at the battle of Monterey. 
During the Civil War, Army engineers built ponton and railroad bridges, constructed forts andbatteries, demolished enemy supply lines, and conducted siege warfare.  In December 1862 theylaid six ponton bridges across the Rappahannock River, under devastating fire from Confederatesharpshooters, in support of the Union attack on Fredericksburg, Virginia.  The 2,170-foot pontonbridge which Union engineer troops laid across the James River in June 1864 as the Army of thePotomac approached Petersburg, Virginia, was the longest floating bridge erected before WorldWar II.  Drawn largely from the top of their West Point classes, the engineers in the Corps beforethe Civil War included many excellent military strategists who rose to leadership roles during thewar.  Among them were Union generals George McClellan, Henry Halleck, and George Meadeand Confederate generals Robert E. Lee, Joseph Johnston, and P. G. T. Beauregard.
**Chapters 1 to 3**       **Chapters 4 to 8**       **Chapters 9 to 15**
**Did you know? — that the gold castle (see *History Sub-page* mastheads below), the distinctive symbol of the Corps of Engineers since 1839, was silver from 1894 to 1921.**
                         
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