Color Barrier officially broken
Although a few black players had been allowed to play professional sports before 1946, it was not until Brooklyn Dodgers owner Branch Rickey signed Jackie Robinson to play major league baseball that the racial barrier broke in all professional sports. Because of this event, Jackie Robinson is the only baseball player in history to have his jersey retired by all thirty teams.
Polidoro, J. Richard (2000) Sport and Physical Activity in the Modern World. Retrieved from pg. 78.