Fort Abraham Lincoln log scouts' quarters. Water was supplied to the fort by being hauled from Missouri River in wagons, while wood was supplied by contract. By 1873, the 7th Cavalry moved into the fort to ensure the expansion of the Northern Pacific Railway. The first post commander of the expanded fort was Lieutenant Colonel George A. Custer, who held the position until his death in 1876. In 1876, the Army departed from here as part of the Great Sioux War of 1876-77, resulting in Custer's defeat at the Battle of the Little Bighorn, where they were to push the non-treaty Indians back
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