On February 2, 1876, the National League of Professional Baseball Clubs, which comes to be more commonly known as the National League (NL), is formed. The American League (AL) was established in 1901 and in 1903, the first World Series was held.
The first official game of baseball in the United States took place in June 1846 in Hoboken, New Jersey. In 1869, the Cincinnati Red Stockings became America’s first professional baseball club. In 1871, the National Association of Professional Base Ball Players was established as the sport’s first “major league.” Five years later, in 1876, Chicago businessman William Hulbert formed the National League of Professional Baseball Clubs to replace the National Association, which he believed was mismanaged and corrupt. The National League had eight original members: the Boston Red Stockings (now the Atlanta Braves), Chicago White Stockings (now the Chicago Cubs), Cincinnati Red Stockings, Hartford Dark Blues, Louisville Grays, Mutual of New York, Philadelphia Athletics and the St. Louis Brown Stockings.
In 1901, the National League’s rival, the American League of Professional Baseball Clubs, was founded. Starting in 1903, the best team from each league began competing against each other in the World Series. Various teams switched in and out of the National League over the years, but it remained an eight-team league for many decades until 1962, when the New York Mets and Houston Colt .45s (later renamed the Houston Astros) joined the league. In 1969, two more teams were added: the San Diego Padres and the Montreal Expos (now the Washington Nationals). Also that year, the league was split into an East and West division of six teams each. The Colorado Rockies and Florida Marlins became part of the National League in 1993, followed by the Arizona Diamondbacks in 1998. In 1994, the league was reorganized to include a Central division, along with the East and West groups.
In 1997, Major League Baseball introduced inter-league play, in which each NL team played a series of regular-season games against AL teams of the same division. (In 2002, the rules were changed to allow AL/NL teams from non-corresponding divisions to compete against each other.)