Harry Longabaugh was born in Pennsylvania in 1867. Sometime in the late 1880's he was arrested for rustling, stealing unbranded cattle, and served 18 months in a prison in Sundance, Wyoming. After his release, he teamed up with Harvey Logan to rob a bank in South Dakota, and a legend was born.

Longabaugh and Logan met Butch Cassidy in 1900 and joined his gang, the Wild Bunch, which included George Curry, Ben Kilpatrick, Will "News" Carver, Laura Bullion, Elza Lay and Bob Meeks. That year Cassidy and the Sundance Kid robbed a Union Pacific train in Wyoming and the First National Bank of Winnemucca, Nevada. Cassidy tried to keep the gang non-violent, insisting that they shoot at horses instead of riders if they were chased, and not hurt people during robberies.

By the end of 1901, most of the Wild Bunch had been killed or arrested. On February 29, 1902, Cassidy, Sundance, and Sundance's girlfriend Etta Place went to South America and purchased land in Argentina. After four years of farming, they decided to become outlaws again and robbed banks around Argentina and Bolivia. This period was famously depicted in the film Butch Cassidy and the Sundance Kid, where the Sundance Kid was played by Robert Redford.

The film portrays the Sundance Kid and Butch Cassidy dying together in a shootout in San Vincent, Bolivia, in 1909, but the two bodies from that incident were never identified. On account says that they were killing during a robbery in Uruguay, while another claims that Longabaugh went back to the United States and died in Wyoming in 1957.