Infantry in the American Civil War The Infantry in the American Civil War comprised foot - soldiers who fought primarily with small arms , and they carried the brunt of the fighting on battlefields across the United States . As the Civil War progressed , battlefield tactics soon changed in response to the new form of warfare being waged in America . The use of military balloons , rifled musket s , repeating rifles , and fortified entrenchment s contributed to the death of many men . General s and other officers , many professionally trained in tactics from the Napoleonic Wars , were often slow to develop changes in tactics in response . Outbreak of war . At the start of the Civil War , the entire United States Army consisted of some 16 , 000 men of all branches , with infantry representing the vast majority of this total . Some of these infantrymen had seen considerable combat experience in the Mexican - American War , as well as in the West in various encounters , including the Utah War and several campaigns against Indians . However , the majority spent their time on garrison or fatigue duty . In general , the majority of the infantry officers were graduates of military schools such as the United States Military Academy . In some cases , individual states , such as New York , had previously organized formal militia infantry regiments , originally to fight Indians in many cases , but by 1861 , they existed mostly for social camaraderie and parades . These organizations were more prevalent in the South , where hundreds of small local militia companies existed . With the secession of eleven Southern states by early 1861 following the election of President Abraham Lincoln , tens of thousands of Southern men flocked to hastily organized companies , which were soon formed into regiment s , brigade s , and small armies , forming the genesis of the Confederate States Army . Lincoln responded by issuing a call for 75 , 000 volunteers , and later even more , to put down the rebellion , and the Northern states responded . The resulting forces came to be known as the Volunteer Army ( even though they were paid ) , versus the Regular Army . Infantry comprised over 80 % of the manpower in these forces . Organization . The typical infantry regiment of the early Civil War consisted of 10 companies ( each with exactly 100 men , according to Hardee ' s 1855 manual , and led by a captain , with associated lieutenant s ) . Field officers normally included a colonel ( commanding ) , lieutenant colonel , and at least one major . With attrition from disease , battle casualties , and transfers , by the mid - war , most regiments averaged 300 - 400 men . Volunteer regiments were paid by the individual states , and officers at first were normally elected by popular vote , or were appointed by the state governors ( particularly the colonels , who were often the men who had raised and organized the regiment ) . As the war progressed , the War Department and superior officers began selecting regimental leaders , and the regimental officers normally selected the NCOs ( non - commissioned officers ) based on performance and merit , although the individual states retained considerable influence in the selection of the regimental officers . Often , and always , according to Hardee ' s 1855 manual , large regiments were broken into two or more battalion s , with the lieutenant colonel and major ( s ) in charge of each battalion . The regiment may have also been divided into two wings , the left and right , for instructional purposes , only . The regimental commander exercised overall tactical control over these officers and usually relied on couriers and staff to deliver and receive messages and orders . Normally positioned in the center of the regiment in battle formation was the color guard , typically five to eight men assigned to carry and protect the regimental and / or national colors , led by a color sergeant . Most Union regiments carried both banners ; the typical Confederate regiment simply had a national standard . Individual regiments ( usually three to five , although the number varied ) were organized and grouped into a larger body ( a brigade ) which soon became the main structure for battlefield maneuvers . Generally , the brigade was commanded by a brigadier general or senior colonel , when merit was clearly evident in that colonel and a Brigadier was not available . Two to four brigades typically comprised a division , which in theory was commanded by a major general , but theory was often not put into practical application , especially when an officer exhibited exceptional merit or the division was smaller and trusted to a more junior officer . Several divisions would constitute a corps , and multiple corps together made up an army , often commanded by a lieutenant general or full general in the Confederate forces , and by a major general in the Union forces . Below is charted the average make - up of the infantry for both sides . Tactics . Commands were typically issued via voice , ( rarely ) drum ( infantry only ) , or bugle call . Soldiers were drilled in infantry tactics , usually based upon a manual written before the war by West Point professor William J . Hardee ( " Rifle and Light Infantry Tactics : for the Instruction , Exercise and Manoeuver of Riflemen and Light Infantry " , published in 1855 ) . Another treatise commonly used was from Winfield Scott , entitled " Infantry Tactics , or Rules for Manoeuvers of the United States Infantry " . Originally published in 1835 , it was the standard drill manual for the U . S . Army . Other popular instruction manuals were issued early in the Civil War , including " McClellan ' s Bayonet Drill " ( 1862 ) and " Casey ' s Infantry Tactics " ( 1862 ) . Many generals , particularly early in the war , preferred to use Napoleonic tactics , despite the increased killing power of period weaponry . They marched their men out in tightly closed formations , often with soldiers elbow - to - elbow in double - rank battle lines , usually in brigade ( by mid - war numbering about 2 , 500 - 3 , 000 infantrymen ) or division ( by mid - war numbering about 6 , 000 - 10 , 000 infantrymen ) strength . This large mass presented an easy target for defenders , who could easily fire several volleys before his enemy would be close enough for hand - to - hand combat . The idea was to close on the enemy ' s position with this mass of soldiers and charge them with the bayonet , convincing the enemy to leave their position or be killed . At times , these soon - to - be outdated tactics contributed to high casualty lists . Of particular tactical importance was the usage of skirmisher s , usually small bodies of advanced troops which were often spaced several yards apart , and more specifically , five paces per man , according to Hardee ' s manual . They screened a defensive line from oncoming enemy soldiers , harassed attackers , probed enemy strength in preparation for an attack , and screened the assaulting columns . However , the skirmish formation was forfeited in most cases , for a line of battle was of preference . Skirmish formation would be used to take up large distances of an open front , which rarely occurred at the larger scale battles . Nevertheless , it was drilled into the recruits , should the opportunity to take skirmish formation arise in a combat scenario . Assaults were carried out in several manners , including single or double rank battle lines with individual regiments side - by - side in a line of battle , assault waves ( with multiple regiments or brigades in successive waves spaced out loosely one behind the other ) , brigade columns ( all regiments of a brigade in line one behind the other in close formation ) , and other formations . Weapons and equipment . Trained in the era of short - range smoothbore musket s , such as the Springfield Model 1842 , which was issued to many units immediately prior to the war , many generals often did not fully appreciate or understand the importance and power of the new weapons introduced during the war , such as the 1861 Springfield musket and comparable rifles which had longer range and were more powerful than the weapons used by the antebellum armies . Its barrel contained several rifle d grooves that provided increased accuracy , and fired a . 58 caliber Minié ball ( a small conical - shaped ball ) . This rifle had a deadly effect up to 600 yards and was capable of seriously wounding a man beyond 1 , 000 yards , unlike the previous muskets used during the American Revolutionary War and Napoleonic Wars , most of which had an effective range of only 100 yards . Even smoothbore muskets underwent improvements : soldiers developed the technique of " buck and ball , " loading the muskets with a combination of small pellets and a single round ball , effectively making their fire scattergun - like in effect . Other infantrymen went into combat armed with shotgun s , pistol s , knives , and assorted other killing instruments . Very early in the war , a few companies were armed with pikes . However , by the end of 1862 , most infantrymen were armed with rifles , including imports from Great Britain , Belgium , and other European countries . The typical Union soldier carried his musket , percussion cap box , cartridge box , a canteen , a knapsack , and other accouterments , in addition to any personal effects . By contrast , many Southern soldiers carried their possessions in a blanket roll worn around the shoulder and tied at the waist . They might have a wooden canteen , a linen or cotton haversack for food , and a knife or similar sidearm , as well as their musket . One primary account of the typical infantryman came from James Gall , a representative of the United States Sanitary Commission , who observed Confederate infantrymen of Maj . Gen . Jubal A . Early in camp in the occupied borough of York , Pennsylvania , in late June 1863 .