The National League is the older of the two leagues constituting Major League Baseball. The League was founded in 1876. The American League was founded in 1900. The league originated from the National Association of Baseball (NA), which was the prevailing professional baseball league at the time.
National League : The first professional baseball team was the Cincinnati Red Stockings, which later became the Reds and were the charter franchise of the National League. The National League was established in 1876 and had franchises in eight cities, including Chicago, Cincinnati, Philadelphia, Boston, Hartford, New York City, St. Louis and Louisville. The league would eventually add four more franchises before the end of the 19th century, but it would also eliminate four teams in 1900 to return to an eight-team league. That opened up the opportunity for a new league to form.
American League : The American League began play in 1900, in part because of the void created when the National League eliminated four teams. The American League had franchises in Boston, Baltimore, Cleveland, Chicago, Detroit, Milwaukee, Philadelphia and Washington. At first, the American League did not compete with the National League and did not consider itself a second major league. However, by 1903, the American League declared itself on par with the National League and challenged that league's winner to meet the American League champion in a series of games to decide the annual baseball championship.
answered May 30 '11 at 03:32