Detroit Tigers, American professional baseball team based in Detroit that plays in the American League. The Tigers have won four World Series titles and 11 AL pennants. The Tigers were founded in 1894 as a minor league franchise, playing alongside organizations that would become the Chicago White Sox, the Cleveland Indians, and the Baltimore Orioles in the Western League. The Western League was renamed the American League in 1900, and it was elevated to major league status in 1901. The early Tiger teams were not a success until Detroit acquired outfielder Ty Cobb—one of the game’s all-time greats—in 1905. In just his third season, Cobb led the team to its first pennant and berth in the World Series, which it lost to the Chicago Cubs. The Tigers returned to the World Series in each of the following two seasons but lost on each occasion.