Robert M. Utley is a preeminent historian of the West and the author of numerous award-winning books, including The Last Days of the Sioux Nation; Frontiersmen in Blue: The United States Army and the Indian, 1848-1865 (Nebraska, 1981); Custer and the Great Controversy: The Origin and Development of a Legend (Nebraska, 1998); and Billy the Kid: A Short and Violent Life (Bison Books, 1991).