This United States military post was established as Fort McKeen on June 14, 1872, by Companies B and C of the 6th Infantry under the command of Lieutenant-Colonel Daniel Huston Jr. It was named in commemoration of Colonel H. Boyd McKeen of the 81st Pennsylvania Volunteer, who lost his life in the Battle of Cold Harbor during the Civil War. The post's name changed to Fort Abraham Lincoln on November 19, 1872. With the establishment of the cavalry post the next year on the flat below, the name Abraham Lincoln designated both garrisons. The primary purpose of these posts was to protect the surveyors and construction parties of the Northern Pacific Railway. Indian raids at and near this site were quite common during 1872 and 1873, and on a number of occasions small detachments of troops from the post were attacked by Indians lying in ambush along the trail a short distance from the fort. Favorite spots for these ambushes were the brushy ravines immediately to the north of the blockhouses. In several instances the Indians forced the soldiers to return to the blockhouses, where additional help was summoned to drive the Indians away. When the Fort Lincoln troops were engaged in the Campaign of 1876, the Indians attacked the outer guards at this post on several occasions. During the most active years of Fort Abraham Lincoln, infantry troops were stationed at this site while cavalry troops were stationed at the cavalry post below. In the latter years of Fort Lincoln, the government dismantled the buildings on this site and moved the lumber down to the cavalry post. After this time the troops were stationed at the cavalry post only. The present blockhouses were restored in 1933 on the original sites.