John L. Sullivan (1858-1918) was an American pugilist, born in Boston, Massachussets. Sullivan became a professional prize fighter in 1878; in 1882 he won the world's heavyweight championship by knocking out Paddy Ryan, champion since 1880, in the ninth round of a contest fought at Mississippi City, Miss. This contest was fought with bare knuckles under London Prize Ring rules; Sullivan remained the bare-knuckle heavyweight champion of the world until his death. However, in many of the contests in which he engaged after 1882 Sullivan fought with boxing gloves under the Marquis of Queensberry rules, then coming into favor; and in 1892 he fought the American pugilist James J. Corbett to determine the first heavyweight champion of the world under Marquis of Queensberry rules. In this fight, which was held at New Orleans, La., for a purse of $25,000 and a side bet of $10,000, Sullivan was knocked out by Corbett in the first round. Sullivan's last-known appearance; in the ring was in a benefit contest in 1896.
During his career he engaged in thirty-seven matches; he won twelve by knockouts and twenty by decisions, drew three, and was knocked out once. His unusual strength earned him the sobriquet "the Boston strong boy"; and his personal popularity, together with adoption of the Marquis of Queensberry rules which eliminated many of the brutal aspects of prize fighting, did much to advance public interest in the sport.