| 4th Corps Army of the Potomac |
4th Corps Army of the Cumberland |
|---|
Piedmont Flag Company
Fourth Army Corps.
September 12, 1862.--The President directed that the corps arranged as the Fourth in General Orders No. 101, of March 13, 1862, Headquarters of the Army of the Potomac, should be known as such. August 1, 1863.--Discontinued, and the troops transferred to other corps.
September 28, 1863.--The Twentieth and Twenty first Corps consolidated and constituted the Fourth Corps, under command of Major-General Gordon Granger.
August 1, 1865.--Discontinued.
Army of the Cumberland.
The Army of the Ohio, commanded by General Don Carlos Buell, became, October 24, 1862, the Army of the Cumberland, and was placed under the command of Major-General W. S. Rosecrans; it was also organized at the same time as the Fourteenth Corps. In January, 1863, it was divided into three corps, the Fourteenth, Twentieth, and Twenty-first; in September, 1863, the Twentieth and Twenty-first Corps were consolidated into the Fourth Corps. October, 1863, General George H. Thomas took command of the army, and the Eleventh and Twelfth Corps were added to it. In January, 1864, the Eleventh and Twelfth Corps were consolidated and known as the Twentieth Corps.