On January 28, 1901, professional baseball’s American League is founded in Milwaukee. The league plans for a 140-game schedule, 14-man rosters and a players’ union. Franchises are in Baltimore (Orioles), Boston (Americans), Chicago (White Stockings), Cleveland (Blues), Detroit (Tigers), Milwaukee (Brewers), Philadelphia (Athletics) and Washington (Senators).
The American League's formation came shortly after professional baseball’s other major league, the National League, contracted from 12 to eight teams. Formed in 1876, the NL had been professional baseball’s most stable league for decades.
Other leagues, such as the American Association (established in 1881), the Union Association (1884) and the Players League (1890), struggled to compete with the NL.
The American League’s attempt to disrupt the National League’s monopoly on baseball was led by its commissioner, Bancroft Johnson. He renamed the Western League, a minor league, the American League in 1899. Johnson also withdrew from the National Agreement—a pact governing relations between the baseball leagues at the time—and, in 1901, declared the American League to be a major league.
The move was resisted by the National League, which wanted to maintain its monopoly on Major League Baseball.
“The National League is forcing this war on us,” . “All we ask is a chance for good, healthy rivalry and competition, but if the National League insists on fighting we shall be able to take care of ourselves.”
Eventually, the National League realized it needed to co-exist with the American League. In 1903, the leagues and that their champion would meet annually in the World Series.