Butch Cassidy and the Sundance Kid, also known by their aliases, were two of the most famous outlaws in American history. The ALIAS of Butch Cassidy was Robert Leroy Parker, while the ALIAS of the Sundance Kid was Harry Alonzo Longabaugh. They were members of the Wild Bunch gang, which was active in the late 19th century in the American West. They were known for their daring robberies of banks and trains, and their exploits were romanticized in the 1969 film Butch Cassidy and the Sundance Kid.