In the mid-1850s, a baseball craze hit the New York metropolitan area.[17] By 1856, local journals were referring to baseball as the "national pastime" or "national game".[18] A year later, sixteen area clubs formed the sport's first governing body, the National Association of Base Ball Players. In 1858 in Corona, Queens New York, at the Fashion Race Course, the first games of baseball to charge admission took place. The games, which took place between the all stars of Brooklyn, including players from the Brooklyn Atlantics, Excelsior of Brooklyn, Putnams and Eckford of Brooklyn, and the All Stars of New York (Manhattan), including players from the New York Knickerbockers, Gothams (predecessors of the San Francisco Giants), Eagles and Empire, are commonly believed to be the first all-star baseball games. [19] [20] [21] In 1863, the organization disallowed putouts made by catching a fair ball on the first bounce. Four years later, it barred participation by African Americans.[22] The game's commercial potential was developing: in 1869 the first fully professional baseball club, the Cincinnati Red Stockings, was formed and went undefeated against a schedule of semipro and amateur teams.[23] The first professional league, the National Association of Professional Base Ball Players, lasted from 1871 to 1875; scholars dispute its status as a major league.[24]
The more formally structured National League was founded in 1876. As the oldest surviving major league, the National League is sometimes referred to as the "senior circuit".[25] Several other major leagues formed and failed. In 1884, African American Moses Walker (and, briefly, his brother Welday) played in one of these, the American Association.[26] An injury ended Walker's major league career, and by the early 1890s, a gentlemen's agreement in the form of the baseball color line effectively barred black players from the white-owned professional leagues, major and minor.[27] Professional Negro leagues formed, but quickly folded. Several independent African American teams succeeded as barnstormers.[28] Also in 1884, overhand pitching was legalized.[29] In 1887, softball, under the name of indoor baseball or indoor-outdoor, was invented as a winter version of the parent game.[30] Virtually all of the modern baseball rules were in place by 1893; the last major change—counting foul balls as strikes—was instituted in 1901.[29] The National League's first successful counterpart, the American League, which evolved from the minor Western League, was established that year.[31] The two leagues, each with eight teams, were rivals that fought for the best players, often disregarding each other's contracts and engaging in bitter legal disputes.[32]

The New York Giants baseball team, 1913. Fred Merkle, sixth in line, committed a baserunning gaffe in a crucial 1908 game that became famous as Merkle's Boner.
A modicum of peace was eventually established, leading to the National Agreement of 1903. The pact formalized relations both between the two major leagues and between them and the National Association of Professional Base Ball Leagues, representing most of the country's minor professional leagues.[33] The World Series, pitting the two