There have been a number of brothers, fathers and sons to play baseball or be involved in the business of the Negro Leagues. However, no family was more involved than the Bankhead Family of Empire, Alabama. Five brothers played in the Negro Leagues.
The oldest and most prolific was Sam Bankhead (1905-1976) who played several positions and managed in the Negro Leagues from 1930-1950. Fred Bankhead (1912-1972) played infield for a number of teams from 1936-1948.
Perhaps the most famous brother was Dan Bankhead (1920-1976) who was pitcher in the Negro Leagues from 1940-1947. In 1947, he became the first black pitcher to integrate the major leagues in the modern era when he pitched for the Brooklyn Dodgers, becoming Jackie Robinson's roommate.
Joe Bankhead (1926-1988) and Garnett Bankhead (1928-1991) both had brief careers in the leagues between 1947 and 1949. Yet, in spite of all this baseball experience, only Fred and Dan got to play on the same team together (the Memphis Red Sox) for a couple of years in 1946 and 1947.
Sources:
Dick Clark and Larry Lester, The Negro Leagues Book, University of Nebraska Press, 1994.
James A. Riley, The Biographical Encyclopedia of the Negro Baseball Leagues, New York: Carroll & Graf Publishers, Inc., 1994.