<Li> ESPN / ESPN2 </Li> <Tr> <Th> Official website </Th> <Td> mlb.com </Td> </Tr> <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 operated as separate legal entities from 1876 and 1901 respectively . After cooperating but remaining legally separate entities since 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> Baseball's first professional team was founded in Cincinnati in 1869, 30 years after Abner Doubleday supposedly invented the game of baseball . The first few decades of professional baseball were characterized by rivalries between leagues and by players who often jumped from one team or league to another . The period before 1920 in baseball was known as the dead - ball era; players rarely hit home runs during this time . Baseball survived a conspiracy to fix the 1919 World Series, which came to be known as the Black Sox Scandal . The sport rose in popularity in the 1920s, and survived potential downturns during the Great Depression and World War II . Shortly after the war, baseball's color barrier was broken by Jackie Robinson . </P>

How many teams are in the mlb national league