Long before Paul Newman and Robert Redford immortalized them on screen, Butch Cassidy and the Sundance Kid captivated Americans from coast to coast. In the 1890s, their exploits robbing banks and trains in the West - and then seemingly vanishing into thin air - became national news and the basis of rumors and myth. But who were Robert Leroy Parker and Harry Alonzo Longabaugh? Find out in AMERICAN EXPERIENCE: BUTCH CASSIDY & SUNDANCE KID.