Black Hawk and his fellow prisoners were discharged from Fortress Monroe.

The evidence

• “September 15 to 21, 1832, a treaty of peace was signed by the AVinnebagoes at Fort Armstrong, Rock Island, and Black Hawk was held as a hostage during the winter at Jefferson Barracks. In April, 1833, he was taken to Washington, D. C, along with the prophet and Neapope, and they were kept as prisoners in Fortress Monroe until June 4 and then discharged.”

  1908-brown-rock-county/03-black-hawk-war.md, Vol. 1, PDF p. 57 / book p. 47

  Brown, William Fiske, editor. Rock County, Wisconsin: A New History of Its Cities, Villages, Towns, Citizens and Varied Interests, from the Earliest Times, Up to Date. Chicago: C. F. Cooper & Co., 1908. 2 vols. archive.org/details/rockcountywiscon01brow, archive.org/details/rockcountywiscon02brow.

  Grade A: Found on a page of one of our sources