Civil War Research
Union forces comprised the equivalent of 2,047 regiments during the Civil War, of which 1,696 were infantry, 272 were cavalry, and 78 were artillery. Unfortunately, few of these have unit histories in any great detail. Frederick H. Dyer, A Compendium of the War of the Rebellion, vol. III, purports to have capsule histories of all of these regiments. It is hoped that many more regimental histories will be published over time.
ORGANIZATION OF THE ARMY
COMPANY The smallest organization in a volunteer regiment. It was commanded by a Captain, assisted by a First Lieutenant and a Second Lieutenant. At organization, it would have a First Sergeant, four Sergeants, and eight Corporals, two Musicians, a Wagoner, and between 64 and 80 privates. Companies were labeled by a single letter. Infantry Regiments had 10 Companies and Cavalry Regiments had 12 Companies. Infantry Companies were labeled A through K (the letter J was not used to avoid confusion). Cavalry Companies were labeled A through M. The equivalent of companies for Artillery Regiments were batteries. (more information)
BATTALION This term refers to an organization of less than full-regimental strength. For volunteer regiments that had been reduced in size due to losses from battle or disease, the remaining troops were sometimes consolidated into full-strength companies. The organization of these companies was referred to as a battalion using the same regimental number. As recruits were added to refill older regiments or battalions, the name of the unit could be changed back to regiment to indicate it had ten companies. A Battalion would usually have between three and six companies.
Regiments of theUS Regular Army were organized into 3 battalions of 6 companies each.
REGIMENT The largest organization allowed to be raised by the states during the war. Regiments could be either Infantry, Cavalry, or Artillery. Infantry Regiments contained 10 Companies (Cavalry had 12) and was commanded by a Colonel, assisted by a Lieutenant Colonel and a Major. At organization, a regiment number approximately 1100 men, though the numbers dropped significantly due to losses from battle and disease. At various times throughout the war,Illinois regiments were strengthened by the addition of new recruits. The term of service for soldiers in a regiment was set at its initial muster, but was most often three years. (more information)
BRIGADE An organization of infantry regiments that was the basic fighting unit during the Civil War. It usually numbered approximately 2000 men. Early in the war, brigades existed with only two regiments. As the war dragged on and regiments shrank in size from losses due to battle or disease, the number of regiments in a brigade increased to keep the number of men about the same. For example, in early 1862, what would become the "Illinois Brigade" included only the 22nd and the 51st regiments. At Stones River at the end of 1862, the Brigade included 4 regiments as well as a battery of artillery. At Chattanooga (Nov 1863), the Brigade had 9 regiments. Brigades were normally commanded by Colonel or Brigadier General. The Union Army number Brigades within Divisions, but battle reports often refer to them by the name of their commander (i.e. Harker’s Brigade).
DIVISION An organization of several Brigades (normally three) under the command of either a Major General or a Brigadier General. Before the Corps structure developed, Divisions were numbered sequentially regardless of how they were grouped. By mid-1862, Divisions were numbered sequentially within Corps.
WING A group of Divisions that was used in the Western theater before the Corps structure developed. The Wing structure was used by the Army of theCumberland at Stones River.
CORPS A group of more than one Division (normally three) under the command of a Major General. Later in the war, Corps developed distinctive badges to tell one from another (see example). Unfortunately, the same Corps Number was sometimes used in both the eastern and western theaters of the war. In the AGR, this was sometimes abbreviated as A.C. (Army Corps).
ARMY A group of more than one Corps under the command of a Major General. Union Armies were named after their Department and thus were named after rivers (Army of theCumberland, Army of the Potomac, Army of the Tennessee, etc.). Confederate Armies were named after states. The Army of Tennessee was a Confederate Army. The Army of the Tennessee was a Union Army.
DEPARTMENT TheUnion divided responsibilty geographically into Departments. The Commander was responsible for all troops and supplies within the Department, in addition to leading those troops against the enemy.
MILITARY DIVISION In 1864,Lincoln consolidated the command of all Union Armies under Lt. General U.S. Grant. The Western armies into the Military Division of the Mississippi under Maj. Gen. William T. Sherman. The Military Division of the Mississippi consisted of the Armies of the Cumberland, Ohio, and Tennessee. Today, this would be considered an Army Group.
DISTRICT A subdivision of a military Department.
BREVET An appointment to a higher rank for command purposes without the corresponding increase in pay.
CONSOLIDATION Regiments were frequently reduced in size by battle or disease. When too many men had been lost to effectively operate with the original command structure, the regiment was consolidated. The men were reorganized into as many full-strength companies as could be made. The best officers were selected to lead the reorganized companies. Any officers left over from the old regiment were declared to be supernumerary and discharged from the service. The consolidated regiment retained the regiment number of the original regiment, but was often referred to as a battalion, unless recruits filled the organization out to a full-strength regiment.
DATE OF RANK The date at which an officers commission is issued. This date is used for determining seniority. When the commander of an organization (i.e., Regiment, Brigade) was wounded or killed, command would initially pass to the most senior officer of the highest rank in that organization.
COMMISSION A formal warrant confering the rank and authority to command men in the army. Officers recieved a commission and were required to take an oath of allegience.
OFFICER A Leader holding a formal commission from the Governor of the State. This includes General Officers, Field Officers, Staff Officers, and Line Officers.
VETERAN RESERVE CORPS See Invalid Corps. Abbreviation: Vet. Res. Corps. Or V.R.C.
INVALID CORPS In 1862, the Invalid Corps was created to utilize wounded or somewhat incapacitated soldiers who could perform limited service such as guard duty, but who were not able to withstand the rigors of service with the armies in the field. A secondary benefit was that it allowed injured soldiers to continue to provide service rather than being a drain on their local areas, and it freed up able-bodied soldiers for field duty. The Invalid Corps was organized nationally with troops from all states. It was later renamed the Veteran Reserve Corps. (more information) Abbreviation: Inv. Corps.
RESIGNATION Officers in volunteer regiments held commissions from their Governor. Officers were allowed to resign their commissions if they no longer wished to serve. In the early part of the war, a number of commissions were given for political reasons and to others who were not suited for combat commands. By 1862, review boards were set up and all volunteer officers were examined to weed out those not suited for command positions. Those not suited were allowed to resign their commissions honorably. Abbreviation: Res.
ENLISTED Soldiers in the army who do not hold Officers Commissions. This includes both non-commissioned officers, privates, veterans, and recruits. Enlisted soldiers may not resign and are in the army until their term of enlistment is up, they can no longer fulfill the duties of a soldier, or until the government doesn't need them any more.
RANK The term given to the position of a soldier in the army (e.g., Major or Private)
RANKS Common term for privates in the army. As in rank and file.
REDUCED Term used for returning a non-commissioned officer to the ranks. Abbreviation: Red.
DISCHARGED Term used for a soldier leaving the regiment before the term of service has expired. Discharges could be for many reasons, most notably wounds or disability. Abbreviated: Dis. or Disch.
KILLED This term was used for those soldiers who died in battle. Occasionally, it was used for those who died of wounds received in battle.
DIED This term was used for soldiers who died for any reason while in the service except for those who died on the battlefield. This would include any soldier who died of disease or non-battle injuries. Occasionally, the AGR will note that a soldier died of wounds (This would be considered battle wounds and would be referred to as being mortally wounded or MW).
MUSTER The process of taking roll and determining fitness for service. Muster was performed every two months and the results kept on a muster roll. It was used by the army to determine the precise number of soldiers in each rank in a unit. Twice each year at muster, the Articles of War were also read to all the troops. See also Mustering In and Mustering Out. (more information)
MUSTERING IN The first muster for a regiment. By completing the mustering in process, soldiers are accepted for service in the army and are considered under military law for their term of service. Also know as Date of Muster in the AGR.
MUSTERING OUT The last muster for a regiment after which the soldiers are released from the army. This is abbreviated as M.O. in the AGR.
SUBSTITUTE When drafting of troops was initiated, the regulations allowed for the draftees to send a suitable subsitute in their place. Substitutes were generally paid by draftees in order to avoid army service. Abbreviation: Sub.