Interleague play
Interleague play in Major League Baseball refers to regular-season baseball games played between an American League (AL) team and a National League (NL) team. Interleague play was first introduced in the 1997 Major League Baseball season. Prior to that, matchups between AL teams and NL teams only occurred during spring training, other exhibition games (such as the Hall of Fame Game in Cooperstown, New York), and the World Series. Unlike modern interleague play, none of these contests, except for the World Series, counted toward official team or league records.
History
Early discussions
Regular season interleague play was discussed for baseball's major leagues as early as 1903, when the two major leagues made peace and formed the National Commission as governing body. The first National Commission Chairman, Cincinnati President Augustus Hermmann, who had already been a proponent of interleague play, proposed an ambitious scheme in late-1904. His plan would've seen the two leagues' ending their seasons earlier, after approximately 116 games, "and then have every National League team play two games in every American League city, and have every American League team play two games in every National League city." Another interleague play idea was floated around the same time by Boston Americans owner John Taylor, whose plan was for each league to play its full 154-game schedule, to be followed by not just a championship series between the two league winners, but also by series' between the two second-place finishers, the two third-place teams, and all other corresponding finishers.