A subdivision of the Division of the Missouri, the Department of Dakota was established by the United States Army on August 11, 1866, to encompass all military activities and forts within Minnesota, Dakota Territory and Montana Territory. The Department of Dakota was initially headquartered at Fort Snelling, Minnesota, and then moved to Saint Paul in March 1867. The 18th Infantry Regiment (United States) would serve in Dakota several times. From 1869-1877 the 20th Infantry Regiment (United States) was posted to the Department. In 1879 the Department returned to the Fort until 1886 at which time it moved back to downtown Saint Paul. The department was discontinued in 1911.

Commanders

Forts

Minnesota

Dakota Territory

Montana

North Dakota

South Dakota

Wyoming

(Wyoming Territory became attached to the Department of the Platte on July 25, 1868)