The Treaty of Traverse des Sioux of 1851 is an agreement between the Sisseton and Wahpeton bands of Dakota and the U.S. government. It transferred ownership of much of southern and western Minnesota from the Dakota to the United States. The treaty is significant in Minnesota's history because, along with the Treaty of Mendota signed that same year, it opened twenty-four million acres of land to immigration. For the Dakota, these treaties marked another step in the process that saw them increasingly marginalized in and dismissed from land that was their home.
The U.S.–Dakota War of 1862 was a turning point in Minnesota history. Joseph Godfrey, an enslaved man , joined the Dakota in their fight against white settlers that summer and fall. He was one of only two African Americans to do so.