that was the baseball league... but yes... it was professional sports.
The Black Fives Era In Perspective
Just after the game of basketball was invented in 1891, teams were called “fives” in reference to their five starting players.
Basketball, like American society, was racially segregated. Teams made up entirely of African American players were often known as “colored quints,” “Negro cagers,” or “black fives.”
The sport remained divided from 1904 — when basketball was first introduced to African Americans on a wide scale organized basis — until the racial integration of the National Basketball League in the 1940s and the National Basketball Association in 1950.
http://www.blackfives.org/about/
and the guy making this inane suggestion about segregated leagues...cant do a simple search on the net yet??