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
Great Sioux War of 1876 To combat the Sioux the U.S. army had a string of forts ringing the Great Sioux Reservation and unceded territory. The largest force arrayed against the Indians at one time was in summer 1876 and consisted of 2,500 soldiers deployed in the unceded territory and accompanied by hundreds of Indian scouts and civilians. Many of the soldiers were recent immigrants and inexperienced on the frontier and in Indian warfare. Cavalry soldiers were armed with .45 caliber, single-action revolvers and the Springfield Model 1873, a single-shot, breech-loading rifle which gave the soldiers a large advantage in range over most Indian weapons.