The Chicago Cubs by YuC

Question 3

In the film "Back to the Future II," Marty arrives in the year 2015 to find, among other things, that the Cubs have won the World Series. According to the film, the Cubs won the 2015 World Series by defeating a team from WHAT CITY, who, at the time of the making of the film, did not have a Major League Baseball team, and now has one, that under current league alignments, cannot meet the Cubs in the World Series?