That matchup had taken place on that field dozens of times, but the Bears' 35-17 win over Green Bay would turn out to be historic for another reason -- it was the Bears' final game at Wrigley Field. Jack Concannon threw four touchdown passes and Cooper Rollow wrote of his performance in the Tribune:
Jack Concannon for President! And anyone who doesn't agree just isn't a Bears fan. Concannon, the much-maligned quarterback who is still wearing Chicago colors only due to the loquaciousness of Virgil Carter, yesterday ramrodded the Bears to victory over the Green Bay Packers.
* The "loquaciousness" referred to above was Carter calling Bears owner George Halas "chicken shit" (the papers of the time all said "chicken bleep") over a contract dispute.
Anyway, the Bears leaving Wrigley wasn't known at the time -- Cooper Rollow reported in the Tribune that 44,957 attended the game, about 2,000 below Wrigley's football capacity, and surely they would have sold out the final game there if people had known -- because well into 1971, the Bears hadn't figured out where they were going to play the following season.
The NFL had mandated that, following the NFL/AFL merger taking effect in 1970, that all stadiums needed to have a capacity of at least 50,000. As noted above, Wrigley was about 3,000 short of that number. Still, the Bears seemed willing to at least consider playing another season at Wrigley Field, though the Tribune had noted that Halas had signed only a one-year deal with P.K. Wrigley for 1970, rather than the three-year contracts he had done in the past with the Cubs' owner, who blasted Halas in a Tribune article published March 23, 1971:
"I have no definite answer on this matter," said the owner of the Cubs and Wrigley Field. "I've got to talk to Halas first if he deigns to talk to me." Wrigley made it clear he was displeased on a couple of counts with the way Halas conducts his Bear business. "I resent the fact that George prints tickets each year before his lease is signed." "And I didn't like it when I had to read in the newspapers that the Bears were trying to move to Dyche Stadium. I wasn't consulted." Asked whether the Bears would be welcome guests again, Wrigley replied, "Not particularly. Halas thinks he has grandfather rights in Wrigley Field. That's something you get if you went into business before the patent laws went into effect."
Two dinosaurs, fighting it out over a business arrangement as if it were still the early 1920s, when the Bears first started playing at Wrigley. As noted, the Bears had discussed playing in Comiskey Park in 1971, going so far as to ask the White Sox for a seating plan for football in their park, which had hosted the Chicago Cardinals until 1958.
The Bears did seriously consider playing in Evanston -- they played their 1970 season opener there -- but the city of Evanston rejected the Bears, and in early April it was still unclear where they'd play, as reported by Rollow:
The Bears have already announced that there will be no sale of individual game tickets over the counter or by mail until June 1. The reason is simple: The Bears don't know where they're going to roost. They tried unsuccessfully to forsake Wrigley Field in favor of Dyche Stadium, and now, Wrigley Field may not welcome them back.
There were also rumors that the Bears might play at Notre Dame Stadium in South Bend; in late April Halas shot down those rumors, and finally, in mid-May 1971, the Bears and the Chicago Park District announced a deal that would put the Bears at Soldier Field for the 1971 season; 42 years and a major renovation later, they're still there.
For many years, Wrigley Field held the title for the stadium that had hosted the most NFL games (344); that mark was later passed by the original Giants Stadium, the L.A. Coliseum, Candlestick Park, Cleveland Stadium, Qualcomm Stadium... and Soldier Field, the current active leader with 358 games.