Compound
1883 national league
25th of January 1919
Indian National Congress
National Basketball League.
William Hulbert formed it out of the National Association, which was the first professional league. Originally the "new" National League contained 4 teams (Chicago, St. Louis, Cincinnati, and Louisville)
The National Football League was founded in 1920 under the name American Professional Football Association. The name was changed to National Football League in 1922.
The National Association was the first major league in baseball and existed between 1871-1875. After it folded the National League was formed and has played continuously since 1876. The American League was founded in 1901.
Starting in 2013 there will be 15 teams in each league (currently there are 16 in the National League and 14 in the American League but Houston will be moving to the AL starting next year). Because there are an odd number of teams, there will always be one team from each league that will have to play outside their league.
The National Hockey League was formed in 1917 in Montreal, it derived from the National Hockey Association which was founded in 1909
The same reason any sport formed, for entertainment of fans
The NFL was formed in 1920 as the American Professional Football Association (APFA) before renaming itself the National Football League for the 1923 season.(from Wikipedia (National Football League)
The National League was formed in in 1876 with the following teams: Chicago, St. Louis, Hartford, Boston, Louisville, New York, Philadelphia and Cincinnati.