Gene Tunney (born this day in 1897) was the heavyweight champ from 1926 to 1928, defeating Jack Dempsey twice in the process. According to Joe Laurie Jr in Vaudeville: From Honky Tonks to the Palace, Tunney, like Dempsey worked in vaudeville at the height of his fame, breaking in the act on the Gus Sun Circuit, but later making as much as $7000 for an engagement at Loews State. Tunney also appeared in some silent films. He passed away in 1978.
To learn more about vaudeville, consult No Applause, Just Throw Money: The Book That Made Vaudeville Famous, available at Amazon, Barnes and Noble, and wherever nutty books are sold.