After the war, American officials learned that some Ho-Chunks had aided Black Hawk more than had been previously known. Eight Ho-Chunks were briefly imprisoned at Fort Winnebago for their role in the war, but charges against them were eventually dropped due to a lack of witnesses. In September 1832, General Scott and Governor Reynolds conducted a treaty with the Ho-Chunks at Rock Island. The Ho-Chunks ceded all their land south of the Wisconsin River in exchange for a forty-mile strip of land in Iowa and annual payments of $10,000 for twenty-seven years. The land in Iowa was known as the "Neutral Ground" because it had been designated in 1830 as a buffer zone between the Dakotas and their enemies to the south, the Sauks and Meskwakis. Scott hoped that the settlement of the Ho-Chunks in the Neutral Ground would help keep the peace. Ho-Chunks remaining in Wisconsin were pressured to sign a removal treaty in 1837, even though leaders such as Waukon Decorah had been U.S. allies during the Black Hawk War. General Atkinson was assigned to use the army to forcibly relocate those Ho-Chunks who refused to move to Iowa.