Fort Custer was established as a military post in November 1877 by order of President Rutherford B. Haynes and General Phil H. Sheridan. It was garrisoned as one of the important military posts in the Northwest until the government abandoned it in September 1897. The fort was named in honor of General George A. Custer, who was killed in action with his entire command at the Battle of Little Big Horn on June 25, 1876.