The history of baseball in the United States dates to the 19th 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 1830–1850s. Semi-professional baseball clubs followed in the 1860s, and the first professional leagues arrived in the post-American Civil War 1870s.
The earliest known mention of baseball in the United States is either a 1786 diary entry by a Princeton University student who describes playing "baste ball," or a 1791 Pittsfield, Massachusetts, ordinance that barred the playing of baseball within 80 yards (73 m) of the town meeting house and its glass windows. Another early reference reports that base ball was regularly played on Saturdays in 1823 on the outskirts of New York City in an area that today is Greenwich Village. The Olympic Base Ball Club of Philadelphia was organized in 1833.
In 1903, the British-born sportswriter Henry Chadwick published an article speculating that baseball was derived from an English game called rounders, which Chadwick had played as a boy in England. Baseball executive Albert Spalding disagreed, asserting that the game was fundamentally American and had hatched on American soil. To settle the matter, the two men appointed a commission, headed by Abraham Mills, the fourth president of the National League of Professional Baseball Clubs. The commission, which also included six other sports executives, labored for three years, finally declaring that Abner Doubleday had invented the national pastime. Doubleday "never knew that he had invented baseball. But 15 years after his death, he was anointed as the father of the game," writes baseball historian John Thorn. The myth about Doubleday inventing the game of baseball actually came from a Colorado mining engineer who claimed to have been present at the moment of creation. The miner's tale was never corroborated; nonetheless, the myth was born and persists to this day.
The first team to play baseball under modern rules is believed to be the New York Knickerbockers. The club was founded on September 23, 1845, as a breakaway from the earlier Gotham Club. The new club's by-laws committee, William R. Wheaton and William H. Tucker, formulated the Knickerbocker Rules, which, in large part, dealt with organizational matters but which also laid out some new rules of play. One of these prohibited soaking or plugging the runner; under older rules, a fielder could put a runner out by hitting the runner with the thrown ball, as in the common schoolyard game of kickball. The Knickerbocker Rules required fielders to tag or force the runner. The new rules also introduced base paths, foul lines and foul balls; in "town ball" every batted ball was fair, as in cricket, and the lack of runner's lanes led to wild chases around the infield. In the long run, these changes resulted in the focus of baseball being more about the duel between batting and pitching rather than baserunning and fielding.
Initially, Wheaton and Tucker's innovations did not serve the Knickerbockers well. In the first known competitive game between two clubs under the new rules, played at Elysian Fields in Hoboken, New Jersey, on June 19, 1846, the "New York nine" (almost certainly the Gotham Club) humbled the Knickerbockers by a score of 23 to 1. Nevertheless, the Knickerbocker Rules were rapidly adopted by teams in the New York area and their version of baseball became known as the "New York Game" (as opposed to the less rule-bound "Massachusetts Game," played by clubs in New England, and "Philadelphia Town-ball").
In spite of its rapid growth in popularity, baseball had yet to overtake the British import, cricket. As late as 1855, the New York press was still devoting more space to coverage of cricket than to baseball.
At an 1857 convention of sixteen New York area clubs, including the Knickerbockers, the National Association of Base Ball Players (NABBP) was formed. It was the first official organization to govern the sport and the first to establish a championship. The convention also formalized three key features of the game: 90 feet distance between the bases, 9-man teams, and 9-inning games (under the Knickerbocker Rules, games were played to 21 runs). During the Civil War, soldiers from different parts of the United States played baseball together, leading to a more unified national version of the sport. Membership in the NABBP grew to almost 100 clubs by 1865 and to over 400 by 1867, including clubs from as far away as California. Beginning in 1869, the league permitted professional play, addressing a growing practice that had not been previously permitted under its rules. The first and most prominent professional club of the NABBP era was the Cincinnati Red Stockings in Ohio, which went undefeated in 1869 and half of 1870. After the Cincy club broke up at the end of that season, four key members including player/manager Harry Wright moved to Boston under owner and businessman Ivers Whitney Adams and became the "Boston Red Stockings" and the Boston Base Ball Club.
In 1858, at the Fashion Race Course in the Corona neighborhood of Queens (now part of New York City), the first games of baseball to charge admission were played. The All Stars of Brooklyn, including players from the Atlantic, Excelsior, Putnam and Eckford clubs, took on the All Stars of New York (Manhattan), including players from the Knickerbocker, Gotham, Eagle and Empire clubs. These are commonly believed to the first all-star baseball games.
Before the Civil War, baseball competed for public interest with cricket and regional variants of baseball, notably town ball played in Philadelphia and the Massachusetts Game played in New England. In the 1860s, aided by the Civil War, "New York" style baseball expanded into a national game. Baseball began to overtake cricket in popularity, impelled by its much shorter duration relative to the contemporary form of cricket. Several other factors reduced North Americans' cultural loyalty to cricket, as Puritan anti-recreational attitudes and centuries of separation had eroded ties to English sporting culture. William Humber argues there was also less of a social taboo around baseball in the New World than in England, where it was strongly perceived as a children's game, and that Americans preferred a sport where the teams alternated offense and defense more frequently.
As its first governing body, the National Association of Base Ball Players was formed. The NABBP soon expanded into a truly national organization, although most of the strongest clubs remained those based in the country's northeastern part. In its 12-year history as an amateur league, the Atlantic Club of Brooklyn won seven championships, establishing themselves as the first true dynasty in the sport. However, Mutual of New York was widely considered one of the best teams of the era. By the end of 1865, almost 100 clubs were members of the NABBP. By 1867, it ballooned to over 400 members, including some clubs from as far away as California. One of these western clubs, Chicago (dubbed the "White Stockings" by the press for their uniform hosiery), won the championship in 1870. Because of this growth, regional and state organizations began to assume a more prominent role in the governance of the amateur sport at the expense of the NABBP. At the same time, the professionals soon sought a new governing body.
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. 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". 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.