The first base ball convention was held in New York City on January 22, 1857 and was attended by 15 clubs, all from New York. Daniel "Doc" Adams was elected convention president and also was elected to head the Committee on Rules and Regulations. Revisions to the original 20 "Knickerbocker Rules" were made.
The First Baseball League: The National Association of Base Ball Players
On March 10, 1858 another convention was held in New York. During this convention the National Association of Base Ball Players was formed and a committee to draft a constitution and by-laws was appointed. William H. Van Cott, who was the founder and president of the Gotham Club, was elected President. All 22 teams that attended were from New York.
The second annual National Association of Base Ball Players convention held in New York City in 1859 included teams from New Jersey. Membership grew to 49 clubs. In 1860 the annual N.A.B.B.P. convention held in New York City reported the membership at 62 clubs.
The Civil War Takes its Toll
With the advent of the Civil War the membership of the annual conventions declined to as low as 28 in 1863 but following the war ballooned to 202 members in 1866.
First Professional Team
As the game gained interest the move toward professionalism produced the first openly professional club, the 1869 Cincinnati Red Stockings. In previous years many teams secretly paid players, there were rumors of fixed games and the fans wagering before and during matches eventually won out over the "gentlemen's club" theory and the National Association of Professional Base Ball Players was formed on March 17, 1871 in New York City
The National Association of Base Ball Players (NABBP) was the first organization governing American baseball. The NABBP was initially established upon principles of amateurism. The first convention of sixteen New York City area clubs in 1857 practically terminated the Knickerbocker era, when that club privately deliberated on the rules of the game. The last convention, with hundreds of members represented only via state associations, provoked the establishment of separate professional and amateur associations in 1871. The succeeding National Association of Professional Base Ball Players is considered the first professional sports league; through 1875 it governed professional baseball and practically set playing rules for all. Because the amateur successor never attracted many members and it convened only a few times, the NABBP is sometimes called "the amateur Association" in contrast to its professional successor.
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 coming 1869 season. Clubs desiring to pay players were now free to declare themselves professional. Conflict arose, however, between amateur and professional interests. Important issues included how the championship was to be decided and regulating players jumping from one team to another. As a result after three years of this experiment, in 1871 most of the leading professional clubs broke away to found the separate National Association of Professional Base Ball Players (NAPBBP). The earlier NABBP continued for approximately two years thereafter in a more diminished status before disbanding into state and regional organizations of the sport.