He opposed the 1868 Treaty of Fort Laramie and fought against efforts by the United States to take control of the ancestral Sioux lands in the Black Hills area of the Dakota Territory.

Late in life he decided to cooperate with the U.S. and may have been involved in the death of his old ally and rival, Crazy Horse, at Fort Robinson in Nebraska in 1877.

[1] Little Big Man was Crazy Horse's lieutenant and threatened to kill the U.S. government commissioners negotiating with the Sioux for control of the Black Hills in 1875.

It was said the Little Big Man was crafty but with considerable ability and presence while being a recognized trouble maker.

Crazy Horse's last words, uttered to Little Big Man and others after he was bayoneted by the soldier, were "Let me go my friends.