Major League Baseball (MLB) is a professional baseball organization and the oldest major professional sports league in the world. MLB is composed of 30 total teams, divided equally between the National League (NL) and the American League (AL), with 29 in the United States and 1 in Canada. The NL and AL were formed in 1876 and 1901, respectively. Beginning in 1903, the two leagues signed the National Agreement and cooperated but remained legally separate entities until 2000, when they merged into a single organization led by the Commissioner of Baseball. MLB is headquartered in Midtown Manhattan. It is also included as one of the major professional sports leagues in the United States and Canada.