During the late 1960's and early to mid 1970's Chicago nearly lost its American League team, first to Milwaukee when Bud Selig attempted to purchase the team and relocate it to Wisconsin to replace the departed Braves. Then again in the 1970s when the team threatened to leave the Windy City several times, most notably for Seattle.
There is an interesting story behind this, first after Bud Selig failed to convince the American League to abandon the Chicago market for Milwaukee he purchased the Seattle Pilots, a team that began play in 1969 and moved them to Milwaukee renaming the team the Brewers. After only one season of baseball the city of Seattle was without the national past time. This created a lot of heartache and mistrust in Seattle toward Major League Baseball.
By the mid 1970's the White Sox were not drawing very well at all, and were looking to move. Poor play on the field certainly didn't help matters any. Seattle had filed a law suit against the American League for a breach of contract, but the American League didn't want to place another team in the Pacific Northwest until a new stadium was built. Sicks Stadium where the Pilots played in 1969 lived up to its name quite well. While it was a premeir ballpark in the decades prior for a minor league team, it was not fit for a Major League franchise. Convinced that not only will Major League baseball would return, but the National Football League would add an expansion team, the people of King County approved a measure to build a domed stadium in downtown Seattle, later known as the Kingdome.
Corrupt politics were alive and well in baseball in the mid 1970's, as Seattle attempted to lure the White Sox from Chicago, the Oakland A's owner Charles Finley was contemplating moving his team to the Windy City to fill the missing void that the White Sox would have left. In OTL, this very well could have happened had it not been for Bill Veeck who had purchased the White Sox to keep them in Chicago, but lets say Veeck has a stroke shortly before he meets with the owners of the White Sox to discuss buying the team. He's alive but not capable of running a Major League team, so the sell goes to Seattle itnerests. Shortly after the all star break in 1975, it is announced the White Sox have been purchased by a group from the Pacific Northwest with the intentions of moving the team to Seattle for 1976. Ticket sells in Chicago plummet, and the White Sox play the rest of their home games in front of hundreds of fans per game. There is an effort by other American League owners to block the move, Chicago is simply too large of a market to surrender to the National League, the move is not expected to be approved, though there is talks of the American League placing an expansion team in either Chicago or Seattle in 1977.
As the season winds down, Charles Finley announces he is leaving the city of Oakland after 8 seasons to relocate to Chicago. Citing poor attendence even during his teams championship runs, Finley claims the Bay Area can only support one team, and the Giants by all rights is that team. Being from Indiana, Chicago is a natural choice for him. It is suggested by some that Finley take over ownership of the White Sox and allow the A's to move to Seattle, but Finley would have none of it. He built a championship team from scratch once and has no desire to do so again, a deal is worked out however between the new owners of the White Sox and Finley, once the team leaves Chicago for Seattle it will operate under a new name, and the relocated A's can assume the White Sox name and colors. With the issue of a team located in Chicago resolved the American League unanomously approved the move for both teams, this simultaneously resolves the city of Seattle's lawsuit with the League.
After a contest the relocated White Sox team is named the Mariners beating out the Rainiers and the Pilots. The Seattle Mariners will begin play in the Kingdome in April, and the new White Sox team (the former A's) will begin play in Comiskey Park. Although disgruntled fans in the Windy City are excited about the new White Sox team and their chance for making the playoffs and bringing a championship to Chicago, in Seattle fans are equally excited about a new team and the brand new Kingdom, tickets in both cities are selling like hotcakes.
Oakland files its own lawsuit against the American League. The most notable side effect of this weird relocation is the city of Toronto will not get its expansion team in 1977 and will have to wait a while yet, this works to the advantage of the Montreal Expos and Detroit Tigers, but Toronto is a Major League City and both leagues realize this. What happens next?