The history of baseball in the United States dates to the 18th century, when boys and amateur enthusiasts played a baseball-like game by their own informal rules using homemade equipment. The popularity of the sport grew and amateur men’s ball clubs were formed in the 1830–50s. Semi-professional baseball clubs followed in the 1860s, and the first professional leagues arrived in the post-American Civil War 1870s.
The NABBP of America was initially established upon principles of amateurism. However, even early in the Association’s history, some star players such as James Creighton of Excelsior received compensation covertly or indirectly. In 1866, the NABBP investigated Athletic of Philadelphia for paying three players including Lip Pike, but ultimately took no action against either the club or the players. In many cases players, quite openly, received a cut of the gate receipts.[18] Clubs playing challenge series were even accused of agreeing beforehand to split the earlier games to guarantee a decisive (and thus more certain to draw a crowd) “rubber match”.[19] To address this growing practice, and to restore integrity to the game, at its December 1868 meeting the NABBP established a professional category for the 1869 season. Clubs desiring to pay players were now free to declare themselves professional.
The Cincinnati Red Stockings were the first to declare themselves openly professional, and were aggressive in recruiting the best available players. Twelve clubs, including most of the strongest clubs in the NABBP, ultimately declared themselves professional for the 1869 season.