Louisiana Purchase - Asserting U.S. Possession

Asserting U.S. Possession

After the early explorations, the U.S. government sought to establish control of the region, since trade along the Mississippi and Missouri rivers was still dominated by British and French traders from Canada and allied Indians, especially the Sauk and Fox. The United States adapted the former Spanish facility at Fort Bellefontaine as a fur trading post near St. Louis in 1804 for business with the Sauk and Fox. In 1808 two military forts with trading factories were built, Fort Osage along the Missouri River in western present-day Missouri and Fort Madison along the Upper Mississippi River in eastern present-day Iowa. With tensions increasing with Great Britain, in 1809 Fort Bellefontaine was converted to a US military fort, and used for that purpose until 1826.

During the War of 1812, Great Britain and allied Indians defeated U.S. forces in the Upper Mississippi; the US abandoned both Fort Osage and Fort Madison, as it did several U.S. forts built during the war, including Fort Johnson and Fort Shelby. After U.S. ownership of the region was confirmed in the Treaty of Ghent (1814), the U.S. built or expanded forts along the Mississippi and Missouri rivers, including adding to Fort Bellefontaine, and constructing Fort Armstrong (1816) and Fort Edwards (1816) in Illinois, Fort Crawford (1816) in Prairie du Chien Wisconsin, Fort Snelling (1819) in Minnesota, and Fort Atkinson (1819) in Nebraska.