Jack Dempsey Jack Dempsey William Harrison "Jack" Dempsey (June 24, 1895 – May 31, 1983), nicknamed "Kid Blackie" and "The Manassa Mauler", was an American professional boxer who competed from 1914 to 1927, and reigned as the world heavyweight champion from 1919 to 1926. A cultural icon of the 1920s, Dempsey's aggressive fighting style and exceptional punching power made him one of the most popular boxers in history. Many of his fights set financial and attendance records, including the first million-dollar gate. Dempsey is ranked tenth on "The Ring" magazine's list of all-time heavyweights and seventh among its Top 100 Greatest Punchers,
Heavyweight boxing championship records and statistics of 23, 2019. These lists do not include "The Ring" and lineal championship fights after 1921, although they only include title streaks during which the champion captured "The Ring" or lineal title. Keys: As of 23, 2019. As of 23, 2019. Keys: "As of 24 September 2018". This list includes only major titles, and it does not include lineal championships after 1921. Below is a list of longest reigning heavyweight champions in boxing measured by the individual's longest reign. The list includes both "The Ring" and lineal championships. Career total time as champion (for multiple time champions) does not apply.