Arizona Cardinals Review and Information
The Cardinals are the oldest existing football club in the United States, beginning as an amateur athletic club team in Chicago named the Morgan Athletic Club, which was founded by Chicago painter/builder Chris O'Brien in 1898. They began to field a pro team even before the founding of the NFL. O'Brien later moved them to Chicago's Normal Field and the team was renamed The Racine Normals, since they were originally located on Racine Avenue in Chicago. In 1901, O'Brien bought used maroon uniforms from the University of Chicago, the colors of which had by then faded, leading O'Brien to exclaim, "That's not maroon, it's cardinal red!" It was then that the team changed its name to the Racine Cardinals.
The team disbanded in 1906 mostly for lack of local competition, but reformed in 1913. They were forced to suspend operations for a second time in 1918 due to World War I and the outbreak of the Spanish Flu Pandemic. They resumed operations later in the year, and have since operated continuously.
In 1920, the team became a charter member of the American Professional Football Association (which became the NFL in 1922), for a franchise fee of $100USD. The Cardinals and the Bears are the only charter members of the NFL still in existence, though the Green Bay Packers, who joined the league in 1921, existed prior to the formation of the NFL. The person keeping the minutes of the first league meeting, unfamiliar with the nuances of Chicago football, recorded the Cardinals as Racine, Wisconsin. The team was renamed the Chicago Cardinals in 1922 after a team from that city entered the league. That season the team moved to Comiskey Park.
The Bears and Cardinals played each other twice in 1920  as the Racine Cardinals and the Decatur Staleys, making their rivalry the oldest in the NFL. The Bears and Cardinals split the '20 series, with the home team winning in each. In the Cardinals 7-6 victory over the Staleys in their first meeting of the season, each team scored a TD on a fumble recovery, with the Staleys failing their XP try  George Halas' '20 Staleys went on to a 10-1-2 record overall, 5-1-2 in league play. The '20 Akron Pros were the first ever league champions, they finished with a 8-0-3 record, 6-0-3 in league play, ending their season in a 0-0 tie against the Decatur Staleys. Thus, the Racine(Chi) Cardinals defeat of the Decatur Staleys earlier in the '20 season meant that the Pros could simply play not to lose; they wisely did and became champions.
But if the '20 Bears had not lost to the '20 Cardinals, they would have gone into that fateful game with a 11-0-1 record, 6-0-1 in league play. The game would've have literally been the first championship game as well as the first playoff game. The actual game in '20 wasn't because the Buffalo All-Americans (9-1-1 in '20, 4-1-1 in league play, they outscored their opponents 258-32, losing only to the Canton Bulldogs 0-3), Staleys and Pros would've each had 1 loss had the Staleys won and each team likely would've played more games as was allowed under the rules in those days to allow teams to settle parity at the top of the standings.
The '20 Racine(Chi) Cardinals did not allow that to happen though. They took one from their soon-to-be crosstown rivals and at the end of the season that one game meant George Halas and the Decatur Staleys would have to wait one more year to collect the first of their many league championships as the '21 Chicago Staleys. It meant that the '20 Akron Pros could play for a tie and still be assured of being the first ever league champions. But most of all, it meant for certain that the Bears and Cardinals were, and always would be, rivals.
The Cardinals gave the Bears their only defeat in '20, the one loss being the difference between 2nd place Bears and a Bears championship. The 2 teams played to a tie in '21 , when the Bears won all but 2 games, thus the Cardinals came within 1 point of costing the Bears a second consecutive championship in the leagues first 2 years of existence. In '22, the Bears went 9-3-0 , losing to the Cardinals twice. The '22 Bears still edged the Cardinals for 2nd place in the league, but the 2 losses dashed all hopes of the Bears catching the Canton Bulldogs, who took the '22 title . In '23 and '24, the Bears got the better of the Cardinals all 3 times the 2 teams played  . But in '25, the Bears went 0-1-1 against the Cardinals with the tie meaning the Cardinals were only a 1/2 game in front of the '25 Pottsville Maroons heading into their fateful '25 showdown , The Cardinals eventually were awarded the '25 title (see 1925 NFL Championship controversy), but the Cardinals would've been in a much more favorable position had the Bears not fought them to that tie.
Thus, in the first 6 years of the leagues existence, the Bears-Cardinals games had a direct impact on the league championship 4 times. The Bears and Cardinals each took home 1 title during that span. But the Bears nearly cost the Cardinals their title, the Cardinals nearly cost the Bears their title and but for the Cardinals tenacity against the Bears, the Bears very well might have won 2 others. The Bears were such a dominant team against everyone but the Cardinals in those days that from 1920-1925 the Canton Bulldogs, champions in '22 and '23, beat them just 2 times and no other team in the NFL defeated the Bears more than once over that entire 6 year span...except the Cardinals . From 1920-1925, The rival Bears and Cardinals played 10 games; they split them 4-4-2 and established their crosstown rivalry as one of the best and hardest-fought ever.