<P> Major League Baseball ( MLB ) is a professional baseball organization , the oldest of the four major professional sports leagues in the United States and Canada . A total of 30 teams play in the National League ( NL ) and American League ( AL ) , with 15 teams in each league . The NL and AL were formed as separate legal entities in 1876 and 1901 respectively . After cooperating but remaining legally separate entities beginning in 1903 , the leagues merged into a single organization led by the Commissioner of Baseball in 2000 . The organization also oversees Minor League Baseball , which comprises about 240 teams affiliated with the Major League clubs . With the World Baseball Softball Confederation , MLB manages the international World Baseball Classic tournament . </P>
<P> Major League Baseball ( MLB ) is a professional baseball organization , the oldest of the four major professional sports leagues in the United States and Canada . A total of 30 teams play in the National League ( NL ) and American League ( AL ) , with 15 teams in each league . The NL and AL were formed as separate legal entities in 1876 and 1901 respectively . After cooperating but remaining legally separate entities beginning in 1903 , the leagues merged into a single organization led by the Commissioner of Baseball in 2000 . The organization also oversees Minor League Baseball , which comprises about 240 teams affiliated with the Major League clubs . With the World Baseball Softball Confederation , MLB manages the international World Baseball Classic tournament . </P>
when did the national league and american league merge
when did the national league and american league merge
2000
2000