Civil War Brigades

The various Army Corps were organized, for the most part, with three Divisions, each Division containing three Brigades, and each Brigade consisting of five Regiments, making forty-five Regiments of Infantry in a Corps, to which were added about nine Batteries of Light Artillery. The Infantry Regiments consisted of ten Companies, of one hundred and one men each; the Artillery and Cavalry Regiments consisted of twelve companies, of one hundred and three and one hundred and five men each. This form of division was adhered to only as a general rule, and was varied at times to meet temporary exigencies. The greatest variation occurred in the Brigades, the depletion, at times, of some Regiments making additional ones necessary to keep up a proper effective strength. Occasionally a Corps would consist of from four to five Divisions, and during the Atlanta Campaign some Brigades of the Fourth and Fourteenth Corps contained as high as nine Regiments. Fifteen hundred men to a regiment was not an uncommon occurrence, but such irregularities were exceptional, and generally proved to be but temporary arrangements.

In sheer numerical size, the United States raised its largest force of brigades ever in the American Civil War. Between 1861 and 1865 the United States, or Union, forces established over 200 brigades to fight the war. These brigades were almost always part of a higher command, division and army corps, as the division was then considered the Army's basic administrative and organizational unit. The army corps, as a headquarters controlling two or more divisions, made its first appearance in the US Army organizational history. Whileu nit designations evolved during the course of the war, the army corps became the uniquely designated command, retaining its numerical designation even when it was shifted to a different command. Divisions and brigades, on the other hand, were numbered sequentially within their respective higher command and called in official reports by their current commander's name. As an exception to this, before 1863 in the portion of the Army fighting in the Western theater, brigades were numbered sequentially within their respective army.

Similar to events in the Mexican War, the US government called up a large number of volunteers to fight the war. Unlike the Mexican War, the pure numbers of the volunteers dwarfed the small Regular Army. Additionally, regular officers were allowed to accept higher commissions in the volunteer service, thus fairly wrecking the chain of command of the regular units. With recruiting difficulties, the Regular Army, despite being expanded at the beginning of the war, basically withered away during the conflict. The war was fought primarily by the volunteers.

Similarly to the Revolutionary and Mexican Wars, brigades often started with regiments all from the same state, or composed exclusively of regular regiments. Attrition and a virtually nonexistent replacement system broke this down rather quickly. As in the Revolutionary War, commanders sought to keep brigades up to a strength of at least 2,000 men by adding additional regiments, even as the more veteran regiments grew smaller and smaller. Initially the minimum number of regiments in a brigade was two, but this was soon changed to four. At Chancellorsville, Virginia, in 1863, Union brigades averaged 4.7 regiments with a strength of 2,000. At Cold Harbor, Virginia, a year later, they averaged 5.5 regiments with the same strength. In the later stages of the war, whole brigades were amalgamated, as were several whole corps, to retain commands of adequate strength.

Only one brigade retained its organization throughout the entire war, the Vermont Brigade, formally the 2d Brigade, 2d Division, Sixth Corps. This brigade, raised in early 1862, retained the 2d, 3d, 4th, 5th, and 6th Vermont Volunteer Infantry Regiments throughout the war and added the 11th Vermont, formerly the 1st Vermont Heavy Artillery Regiment, in 1864. The brigade was able to stay together because all its regiments re-enlisted when their enlistments ran out in 1864. The brigade also, naturally because of its long, continuous service, suffered the most fatal combat casualties of any brigade in the war, with 1,172 men killed or dying of wounds while serving in its ranks. These losses were distributed almost evenly throughout the brigade.

Four hundred and fifty men were commissioned as brigadier-generals in either the Regular Army or the volunteer service during the Civil War. Theoretically, all brigades were supposed to be commanded by brigadier-generals. However, the creation of the army corps as a level of command and the extensive use of field armies made up of several army corps created two new levels of command. Unfortunately, at the same time, Congress, except for appointing Ulysses S. Grant as the sole lieutenant-general in 1864, did not promote officers past the grade of major-general, the standard grade for a division commander. Accordingly, major-generals commanded armies and corps, as well as divisions. Brigadier-generals frequently commanded divisions, as well as brigades, often by using brevet promotions to major-general. Brigades, therefore, were often commanded by the senior regimental colonel rather than a general officer, most of whom were also brevet brigadier-generals. Authorizing officers to serve in their brevet grade had previously been a right reserved for the president, but in February 1865, this authority was delegated directly to the Army's commanding general, Lieutenant-General Ulysses Grant. For the first time in US military history, the grade of brigadier-general was no longer tied to the number of brigades the Army could assemble. From this time forward, it was simply the lowest grade of general officer.

While being almost purely a tactical unit consisting of only either infantry or cavalry regiments, the Civil War brigade did acquire a small staff as the war progressed: two aides de camp; acaptain assistant adjutant general, who wrote out orders for the command; a surgeon; an assistant quartermaster; and a commissary officer. The brigade headquarters was also authorized three wagons to carry supplies. Each subordinate regiment was authorized an additional six wagons.

Infantry brigades in the Civil War consisted almost exclusively of infantrymen. Early war experiments placing supporting units of artillery and cavalry in the brigade were abandoned. Since brigades seldom fought separated from their parent corps, artillery eventually came tobe consolidated at the corps level in a command, an artillery brigade. Despite the name, a typical corps artillery brigade consisted of between four and six artillery companies and was commanded by an artillery officer, usually a colonel, but sometimes a more junior officer.

Although most brigades served just as a component of a corps, some retained distinctive nicknames even when their official designation changed. A good example of this is the famous Iron Brigade, which earned its nickname at Second Bull Run while officially designated 4th Brigade, 1st Division, Third Corps, Army of Virginia. Later at Gettysburg, Pennsylvania, it re-affirmed its nickname while designated officially as the 1st Brigade, 1st Division, First Corps. Another famous brigade was the Irish Brigade - 2d Brigade, 1st Division, Second Corps - originally composed of regiments recruited from the Irish immigrant population of NewYork City. Both brigades were eventually broken up when combat losses were not replaced.