The American Association of Base Ball Clubs (AA) was a professional baseball league that existed for 10 seasons from 1882 to 1891. Together with the National League (NL), founded in 1876, the AA participated in an early version of the World Series seven times versus the champion of the NL in an interleague championship playoff tournament. At the end of its run, several AA franchises joined the NL. After 1891, the NL existed alone, with each season's champions being awarded the Temple Cup (1894–1897).

The World Series is the annual final championship series of Major League Baseball (MLB) in the United States and Canada. It has traditionally been held in October, though some more recent editions were contested in November due to expanded playoffs and/or season delays. It has been contested since 1903 between the champion teams of the American League (AL) and the National League (NL). The winner of the World Series championship is determined through a best-of-seven playoff, and the winning team is awarded the Commissioner's Trophy.