The NFL's First Game Was Played in Dayton
National Football League - 1920 NFL Season Overview
The Meeting that Started the NFL
NFL founded in Canton on Sept. 17, 1920
Gridiron' tells stories from 100 years of the NFL. But lots of stories wouldn't fit. - The Washington Post
1920 Canton Bulldogs season - Wikipedia
20th August 1920: The NFL established as the American Professional Football Conference
Where is the NFL Hall of Fame and why is it there? - AS USA
More Detail 1920, Professional Football Begins - America's Best History - U.S. History Timeline 1920 to 1929