Racine Cardinals Star 23 Oct 1920, Sat The Daily Times (Davenport, Iowa) Newspapers.com
In September of 1920, O'Brien was invited to attend the famous meeting in Canton, Ohio, that started the APFA, which a few years later would be the National Football League. Chris O'Brien is indeed one of the founders of the League. On November 26, 1920, the Decatur Staleys and the Chicago Cardinals played in an APFA game, and that is proof that the Cardinals and the Bears have the longest-running rivalry in the NFL. The following year, the Cardinals became the first Chicago APFA team to play the Green Bay Packers. One week later, the Bears played the Packers. So, despite what the announcers on television broadcasts say, the Bears and the Packers are the third oldest rivalry of current NFL teams.
Eventually, O'Brien allowed George Halas and the Decatur Staleys to move to Chicago and become the Bears. The Cardinals played in the young NFL and even were awarded the 1925 Championship Title. Chris O'Brien, however, fell on some hard times later, and in 1929, he was forced to sell the franchise to a local Doctor named David Jones.
The Good Doctor 1932 sold the franchise to Charles W. Bidwill, and that started the ownership by the Bidwill family up to the present day. During World War II, the team was forced to merge with the Pittsburgh Steelers due to a player shortage, and this started a 29-game losing streak. The franchise gathered themselves after the war and won another NFL title in 1947. Eventually, the franchise relocated to St. Louis in 1960 and again to Arizona some three decades after that.
To learn more about the Cardinals in detail, please listen to Joe Ziemba's podcast When Football Was Football or read his great book When Football Was Football: The Chicago Cardinals and the Birth of the NFL.