Super Bowl: What NFL isn't commemorating: 12-year ban on black players
NFL History: 100 objects that tell the story of football - Sports Illustrated
George Halas Played Dirty And It Cost Him Once Against a Chippewa Native
George Halas was a pro basketball pioneer as well
NFL history: 100 people who shaped the league, pro football - Sports Illustrated
NFL's Depression-era ban on Black players lingers on in the owner's box - The Philadelphia Sunday Sun
Chicago Bears founder George Halas played a part in everything for NFL - Chicago Sun-Times
The Life And Career Of Jim McMahon (Complete Story)
Chicago Bears founder George Halas played a part in everything for NFL - Chicago Sun-Times