http://www.pro-football-reference.com/players/
Bit ambiguous, but probably the Canton Bulldogs (who were formed in 1905, possibly as a semi-pro team, but went pro in the formation of the NFL in 1920).However, a large number of other teams were formed or went pro in 1920 who might be possible contenders include:Akron Pros / Indians (1920-26)Buffalo All Americans / Bisons / Rangers (1920-29)Chicago Tigers (1920)Cleveland Tigers (1920-21)Columbus Panhandles / Tigers (1920-26)Dayton Triangles (1920-29)Detroit Heralds (1920)Hammond Pros (1920-26)Muncie Flyers (1920-21)Rochester Jeffersons (1920-25)Rock Island Independents (1920-25)Probably the best rival claim is the Akron Pros, who were at least a semi-pro team as early as 1908.
Akron Pros Buffalo All-Americans Decatur Staleys Rock Island Independents Dayton Triangles Chicago Cardinals Canton Bulldogs Cleveland Tigers Detroit Heralds Chicago Tigers Columbus Panhandles Muncie Flyers Rochester Jeffersons Hammond Pros. circa 1920
Mostly blue and white.
November 25, 1920. Three games were played on Thanksgiving Day in the NFL's first season. The Dayton Triangles defeated the Detroit Heralds 28-0, the Decatur Staleys defeated the Chicago Tigers 6-0, and the Akron Pros defeated the Canton Bulldogs 7-0.
the windsor/Detroit border
Ernie Alten debuted on April 17, 1920, playing for the Detroit Tigers at Navin Field; he played his final game on June 30, 1920, playing for the Detroit Tigers at Navin Field.
Harry Baumgartner debuted on September 6, 1920, playing for the Detroit Tigers at Navin Field; he played his final game on October 2, 1920, playing for the Detroit Tigers at Navin Field.
John Bogart debuted on September 17, 1920, playing for the Detroit Tigers at Navin Field; he played his final game on October 3, 1920, playing for the Detroit Tigers at Navin Field.
Davey Claire debuted on September 17, 1920, playing for the Detroit Tigers at Navin Field; he played his final game on September 19, 1920, playing for the Detroit Tigers at Navin Field.
Lou Vedder debuted on September 18, 1920, playing for the Detroit Tigers at Navin Field; he played his final game on September 18, 1920, playing for the Detroit Tigers at Navin Field.
Mutt Wilson debuted on September 11, 1920, playing for the Detroit Tigers at Navin Field; he played his final game on September 18, 1920, playing for the Detroit Tigers at Navin Field.
Frank Okrie debuted on April 18, 1920, playing for the Detroit Tigers at Navin Field; he played his final game on August 4, 1920, playing for the Detroit Tigers at Navin Field.