The National League of Professional Baseball Clubs, or simply the National League (NL), is the older of two leagues constituting Major League Baseball in the United States and Canada, 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 contrast to the "Junior Circuit" of 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. National League teams have won 42 and lost 61 of the 103 World Series played between these two leagues from 1903 to 2007. The Colorado Rockies are the defending National League champions, winning the NL Pennant in 2007.