Fort Abercrombie, the first United States military post established in what is now North Dakota, was authorized at this point in 1857 and named in honor of Lt. Col. John J. Abercrombie. Extensive trade between Canada and the Northwest with St. Paul and other Minnesota points led to the construction of military posts along the route, and the rapid settlement of Minnesota and the proposed settlement of the Red River Valley made a post on the Red River necessary. As the head of navigation on the Red River, this site was a logical location for a military post. The protection provided by Fort Abercrombie enabled new trade routes to be opened and old routes maintained through what would have been hostile Indian country. During the Minnesota uprising of 1862, Fort Abercrombie played a prominent part by protecting white settlers and traders in the vicinity. The fort was attacked by Indians on two occasions and remained under siege for 60 days, but although the attacks were severe, the Indians were beaten off and held at bay until reinforcements arrived from Fort Snelling. Fort Abercrombie continued to serve the Northwest until the rich lands of the Red River Valley were occupied by white settlers, after which the post's usefulness gradually declined and the fort was abandoned.