n 1882 the American Association was formed after its first formal meeting was held in Cincinnati on November 2, 1881. The original franchises were: Baltimore Orioles, Cincinnati Red Stockings (expelled from the National League for selling beer at home games and letting a semi-pro team play games there on Sunday), Louisville Eclipse, Philadelphia Athletics, Pittsburgh Alleghenys and St. Louis Browns. The American Association placed teams in cites unoccupied by the National League and captured both Philadelphia and Cincinnati. At the conclusion of the 1882 season the National League Champion Chicago White Stockings played the American Association Champion Cincinnati Red Stockings, in Cincinnati, with each team winning one game. Some consider this the first "World Series." The two leagues would end the season against each other again in 1884.
The National League appealed to more middle-class audiences by requiring its teams to charge fifty cents admission, banning the sale of alcohol, and refusing to play on Sundays. The rival American Association appealed to immigrant and working-class audiences by charging only a quarter, selling liquor and playing Sunday ball.
In 1884 the Union Association of Professional Base-Ball Clubs was formed by Henry Lucas, a St. Louis lawyer. His league did not institute the "reserve clause," which was used by the National League since September 1879. The reserve clause stated that a certain number of players could be retained by their team for the following season and were not to be persuaded to play for another club. The original Union Association teams were; Altoona Mountain Cities, Baltimore Unions, Boston Reds, Chicago Unions, Cincinnati Outlaw Reds, Philadelphia Keystones, St. Louis Maroons and Washington Nationals. There were now 33 major league base ball teams in the United States. The Union Association lasted only one season.
The American Association and the National League would abide by the same rules for the 1887 season and on November 4, 1889, John Montgomery Ward would help formulate the Players' League. In October of 1885 Ward had formed the Brotherhood of Professional Base Ball Players in an effort to unionize the players and promote their best interests. The Players' League stipulated that there would be no reserve clause, a player could not be traded without his consent and could not be released outright without the approval of the team's board of directors. Original Players' League teams were; Boston Reds, Brooklyn Ward's Wonders, Buffalo Bisons, Chicago Pirates, Cleveland Infants, New York Giants, Philadelphia Quakers and Pittsburgh Burghers. Although The Players' League out drew both the National League and American Association, it folded after only one season.
After the 1891 season on December 18, the National League absorbed four American Association teams (Baltimore Orioles, St. Louis Browns, Louisville Colonels and Washington Senators) and became one 12-team league known as the National League and the American Association of Base Ball Clubs. The name was permanently changed to the National League in 1900. Hence, even today the National League is sometimes referred to as the "Senior Circuit."
The formation of the American League, "The Junior Circuit," would follow in 1901.