Grant, a Native American, was raised on the Omaha Reservation in Macy, Nebraska. After his biological parents abandoned him, his grandparents raised him from six months of age, until 1982. Besides Dances with Wolves, he has also appeared in films such as Ghosts of Mars, Wild Wild West, Geronimo: An American Legend, White Wolves III: Cry of the White Wolf, Wagons East!, The Substitute, War Party, and Powwow Highway. He portrayed "Chingachgook" in the syndicated television series Hawkeye and also had guest roles in television series such as Due South, Two, and the Stargate SG-1 (episode "Spirits"). He also portrayed the famous warrior Crazy Horse in the 1991 television movie Son of the Morning Star.