The league began as the Midwest Football League (MFL), a minor professional American football league that started in 1935, led by George J. Heitzler and James C. Hogan. Originally without major league aspirations, the league changed its name and its aspirations to the American Professional Football League (APFL) in 1938 in order to try to lure teams from the previously failed AFL. Finally, in 1939, it admitted both the Cincinnati Bengals and Los Angeles Bulldogs, two teams that survived the 1937 AFL II collapse and spent the 1938 season as independent teams.
At the end of the 1939 season, the league was preparing to continue as a major league when eastern businessmen lured Cincinnati, Columbus, and Milwaukee to join teams based in Boston, Buffalo, and New York to form a new American Football League III. The resulting split doomed the APFL as two members folded and two others were turned away from membership in the new league.