The National League of Professional Baseball Clubs, which would eventually become the National League of Major League Baseball, was originally formed with eight teams, including the Boston Red Stockings, the Chicago White Stockings, the Cincinnati Red Stockings, the Hartford Dark Blues, the Louisville Greys, Mutual of New York, the Philadelphia Athletics and the St. Louis Brown Stockings. Only two of these teams are still in operation in Major League Baseball.
Of the eight original teams of the National League, only the Boston Red Stockings, which are now the Atlanta Braves, and the Chicago White Stockings, which are now the Chicago Cubs, have been in continuous operation.
Although Major League Baseball counts 1869 as its founding year, which was the year that the first professional team, the Cincinnatti Red Stockings, was established, the American League was not formed until 1901. The two leagues did not interact until 1903, when the best team from each league began competing in the World Series. The National League would continue on with eight teams until 1962, but not all of the original clubs remained active during that time. In 1962, the League's first expansion occurred with the addition of the New York Mets and the Houston Colt .45s, which later became the Astros. The first league divisions were also created that year.