After a tumultuous five-year existence, the National Association of Professional Base Ball Players (NA) folded following the 1875 season. The National League of Professional Base Ball Clubs (NL) was formed in Chicago, Illinois, by businessman and owner of the Chicago Base Ball Club, William Hulbert, for the purpose of replacing the NA, which he believed to have been corrupt, mismanaged, full of rowdy, drunken ballplayers, and under the influence of the gambling community. One of the new rules put into place by the new league was that all teams had to be located in cities that had a population of 75,000 or more. The initial NL season began with eight teams, and they were asked to play seventy games between April 22 and October 21. The NL is often considered to be the first "major league", although it has been argued that the NA can make that claim.

The following is a franchise history of the Chicago Cubs of Major League Baseball, a charter member of the National League who started play in the National Association in 1870 as the Chicago White Stockings. The Chicago National League Ball Club is the only franchise to play continuously in the same city since the formation of the National League in 1876. They are the earliest formed active professional sports club in North America, predating the team now known as the Atlanta Braves by one year. In their early history, they were called in the press the White Stockings, Orphans, Infants, Remnants and Colts before officially becoming "Cubs" in 1907.