Heavyweight unification series Heavyweight unification series The heavyweight unification series, also known as the Heavyweight World Series, was a sequence of professional boxing matches held in 1986 and 1987 to crown an undisputed champion of the heavyweight class. The series was produced by HBO Sports and promoted by Don King. It ended with Mike Tyson as undisputed champion, holding the championship belts of the International Boxing Federation, World Boxing Association, and World Boxing Council. Prior to the series, the last undisputed heavyweight champion had been Leon Spinks, who won the championship in his 1978 victory over Muhammad Ali. Spinks had been stripped of
Professional boxing the era were the peerless heavyweight Jim Jeffries and Bob Fitzsimmons, who weighed less than 12 stone (164 pounds), but won world titles at middleweight (1892), light heavyweight (1903), and heavyweight (1897). Other famous champions included light heavyweight Philadelphia Jack O'Brien and middleweight Tommy Ryan. On May 12, 1902 lightweight Joe Gans became the first black American to be boxing champion. Despite the public's enthusiasm, this was an era of far-reaching regulation of the sport, often with the stated goal of outright prohibition. In 1900, the State of New York enacted the Lewis Law, banned prizefights except for those held