Associations of teams of black baseball players active largely between 1920 and the late 1940s.
The principal leagues were the Negro National League, originally organized by Rube Foster in 1920, and the Negro American League, organized in 1937. The most noted teams included the Homestead (Pa.) Grays, who won nine pennants in the years 1937–45 and included the great hitters Cool Papa Bell , Buck Leonard , and Josh Gibson . In the mid 1930s the Pittsburgh Crawfords included Satchel Paige and the clutch-hitter William Julius "Judy" Johnson. The Kansas City Monarchs, after winning four national championships, lost Jackie Robinson to the Brooklyn Dodgers; the breaking of the colour barrier in major and minor league baseball led to the Negro leagues' decline.