Nearly a century after the Mandan occupied On-a-Slant village, the U.S. military established an infantry post on a bluff above the On-A-Slant ruins. In preparation for the Northern Pacific Railroad to lay its track to the west of the Missouri River basin, the military dispatched to companies of Infantry to the area. In June 1872, an infantry post, called Fort McKeen The name Fort McKeen was short-lived; the designation was changed to Fort Abraham Lincoln on November 19, 1872. In 1873 Congress authorized the addition of a cavalry post and its construction was mostly completed the same year.
By 1874, Fort Abraham Lincoln housed three companies of the 6th and 17th Infantries and six companies of the 7th Cavalry, making the fort a nine-company command. With a total complement of about 650 men, the fort was among the largest and most important forts on the Northern Plains.
Lt. Colonel (Brevet Major General) George Armstrong Custer was the first commander of the enlarged fort and served here from 1873 until the Battle of the Little Big Horn in 1876. Upon completion of the railroad to Montana, Fort Abraham Lincoln had fulfilled its primary purpose. Consequently, the fort gradually declined in importance in 1891 it was decommissioned. In its heyday, the fort encompassed 78 separate buildings. All of the original buildings were dismantled by area settlers and the materials used in the construction of area homes and farms.
How to learn more
Visit Fort Abraham Lincoln State Park and experience what life was like back in 1876. Reconstructed replicas of the commissary storehouse, enlisted men’s barracks, granary and stable are open to walk through. Saturday mornings during the summer, kids can participate in the Life of a Frontier Soldier Program. The Victorian-style home of George and Libbie Custer has been reconstructed and is open for living history tours.