Gene Tunney never fought a black opponent his entire career. I've read that he was not a racist and various reasons to why he never fought people of color have been given over the years. He was willing to meet Harry Wills in match to finalize Dempsey's opponent but Wills refused, feeling he had already earned the right to be Dempsey's next challenger. Dempsey fought at least four people of color and had a 3-0-1 record early in his career. He also had contender Bill Tate as a sparring partner for many years. He signed to fight Harry Wills the top African American contender but the check advance bounced scuttling the fight. I believe the difficulties of Wills securing a title shot had more to do with management of Dempsey and societal view points of the era rather than a personal discrimination from Dempsey himself.