Butch Cassidy was a charming Mormon-born outlaw who led the Wild Bunch gang in a series of daring bank and train robberies across the Western United States. Relentlessly pursued by the Pinkerton Detective Agency, he and the Sundance Kid fled to South America around 1901 to establish a ranch and attempt a new life in Argentina. While official records state he was killed in a 1908 shootout in Bolivia, persistent legends and family accounts suggest he survived and returned to the U.S. under the alias William Thadeus Phillips.Would you like me to find more sources regarding the specific evidence linking William Thadeus Phillips to Butch Cassidy?