Second Treaty of Prairie du Chien

The Treaty of Prairie du Chien may refer to any of several treaties made and signed in Prairie du Chien, Wisconsin between the United States, representatives from the Sioux, Sac and Fox, Menominee, Ioway, Winnebago and the Anishinaabeg (Chippewa, Ottawa and Potawatomi) Native American peoples.

Two treaties were negotiated simultaneously at Prairie du Chien in the summer of 1829, both signed by General John McNeil Jr., Colonel Pierre Menard, and Caleb Atwater for the United States.

By this treaty, the tribes ceded to the United States an area in present-day northwestern Illinois and southwestern Wisconsin, as well as the areas currently occupied by the cities of Wilmette, Evanston, and about half of Chicago.

This treaty established reservation areas in western Illinois for the Prairie Band of Potawatomi Nation.

This treaty also preserved the rights of the Council of Three Fires to hunt in the ceded territory "so long as the same shall remain the property of the United States".