The Black Hawk War marked the end of Native armed resistance to U.S. expansion in the Old Northwest The war provided an opportunity for American officials such as Andrew Jackson, Lewis Cass, and John Reynolds to compel Native American tribes to sell their lands east of the Mississippi River and move to the West, a policy known as Indian removal. Officials conducted a number of treaties after the war to purchase the remaining Native American land claims in the Old Northwest. The Dakotas and Menominees, who won approval from American officials for their role in the war, largely avoided postwar removal pressure until later decades.