John L. Sullivan, a Boston native, is widely credited with helping to bring pro boxing from its nascent bare-knuckle days to the dawn of the modern era. He won the heavyweight championship in 1882, defeating Paddy Ryan in Mississippi. In 1889, he successfully defended his title by defeating Jake Kilrain in a fight that lasted 75 rounds. Sullivan held the title until 1892, when he lost to James J. Corbett.