The Black Hawk War was a conflict between the United States and Native Americans led by Black Hawk, a Sauk leader. The war erupted after Black Hawk and a group of Sauks, Meskwakis (Fox), and Kickapoos, known as the "British Band", crossed the Mississippi River, to the U.S. state of Illinois, from Iowa Indian Territory in April 1832. Black Hawk's motives were ambiguous, but he was apparently hoping to reclaim land that was taken over by the United States in the disputed 1804 Treaty of St. Louis.