Fort Custer (Montana) Fort Custer (Montana) Fort Custer was established during the Indian wars in the Department of Dakota by the U.S. Army to subjugate the Sioux, Cheyenne and Crow Indians near present-day Hardin, Montana. The post was named for General George Armstrong Custer who died at the Battle of the Little Big Horn. In April and May, 1877, three companies (C, F and G) were moved from Cheyenne Agency, and three companies ( A, B and H) from Fort Yates in the Standing Rock Agency to the Little Big Horn, Montana, under the command of Lieut.-Colonel G. P. Buell, 11th Infantry, where
5th Cavalry Regiment Henry Thomas. The regiment was rebuilt with new officers and recruits loyal to the Union and was assigned to the Army of the Potomac under the command of General George McClellan. On 21 July 1861, the regiment participated in its first battle of the American Civil War, the First Battle of Bull Run; it was the last action in which they would be called the "2nd Cavalry." In the summer of 1861, all regular mounted regiments were re-designated as "cavalry", and being last in seniority among the existing regiments, the regiment was re-designated as the 5th United States Cavalry. During