High Quality Content by WIKIPEDIA articles! The National League of Professional Baseball Clubs, known simply as the National League (NL), is the older of two leagues constituting Major League Baseball, and the world's oldest extant professional team sports league. Founded on February 2, 1876, to replace the National Association of Professional Base Ball Players, it is sometimes called the Senior Circuit in comparison to the "Junior Circuit" or the American League, established as a major league in 1901. The two league champions of 1903 arranged to meet in the World Series and, after the 1904 champions failed to do likewise, the two leagues have arranged to meet in that annual culmination of the American baseball season, failing to do so only in the strike-shortened 1994 season.