 White opposition led to their exclusion from most organized sporting competitions.The boxers Jack Johnson and Joe Louis (both of whom became world heavyweight boxing champions) and track and field athlete Jesse Owens (who won four gold medals at the 1936 Summer Olympics in Berlin) earned fame during this era.In baseball, a color line instituted in the 1880s had informally barred blacks from playing in the major leagues, leading to the development of the Negro Leagues, which featured many fine players.