In 1821, he defied his tribe and signed the Treaty of Chicago, ceding all Ottawa territory south of the Grand River to the United States.
[3] Keewaycooshcum was described by one contemporary as: "about middle stature, [with] a face of the sternest aspect marked with a more than usual degree of savage Gloom, with a very compact though active figure.
[4] While the majority of the Grand River Ottawa opposed selling tribal lands to the United States, Keewaycooshcum was persuaded to agree to a sale by Lewis Cass, the future Governor of the Michigan Territory with whom Keewaycooshcum was close friends.
[3] Keewaycooshcum's agreement to the terms of the 1821 treaty substantially hurt his prestige with the Grand River Ottawa.
[5] When the Grand River Ottawa signed a second treaty with the United States in 1836, Keewaycooshcum was singled out with the diminutive title "former head chief," and designated as a "2nd Class" leader.