Shortly after the war, Jackie Robinson broke baseball's color barrier. It survived the Great Depression and World War II. Professional baseball survived the Black Sox Scandal, a conspiracy to fix the 1919 World Series, then rose in popularity in the following decade. The period before 1920 was the dead-ball era, when home runs were rarely hit. The first few decades of professional baseball saw rivalries between leagues, and players often jumped from one team or league to another. īaseball's first all-professional team, the Cincinnati Red Stockings, was founded in 1869. MLB is headquartered in Midtown Manhattan. They remained legally separate entities until 2000, when they merged into a single organization led by the Commissioner of Baseball. Formed in 18, respectively, the NL and AL cemented their cooperation with the National Agreement in 1903, making MLB the oldest major professional sports league in the world. One of the major professional sports leagues in the United States and Canada, MLB comprises 30 teams, divided equally between the National League (NL) and the American League (AL), with 29 in the United States and 1 in Canada. Major League Baseball ( MLB) is a professional baseball organization.