In the mid-19th cent. baseball was primarily popular among local clubs in the Northeast, often made up of members of the same occupation. Eventually, competition broadened, and an organization to promote standardized rules and facilitate scheduling, the National Association of Baseball Players, was formed in 1858. The movement of Union soldiers during the Civil War helped to spread the game, and increased opportunities for leisure, improved communications, and easier travel after the war fostered a wider competitive base and increased interest.
In 1869, Harry Wright organized the Cincinnati Red Stockings, baseball's first professional team, and took them on a 57-game national tour, during which they were unbeaten. Seeking to expand on the Reds' success, the National Association of Professional Baseball Players in 1871 chartered nine teams in eight cities as the first professional league. In the 1870s a number of competing leagues were formed, including the National League, which soon became the predominant association.
Financial hardships, gambling-related scandals, and franchise upheaval plagued all the leagues, and a players' revolt in 1890, which resulted in a short-lived Players Association, weakened the National League. A competing league, the Western Association, changed its name to the American League in 1900 and placed clubs in several eastern cities. In 1903 the champions of the American and National leagues met for the first time in what became known as the World Series.
Both leagues fought off the challenge of the Federal League in 1914-15, but baseball's popularity and stability were threatened when the 1919 Chicago White Sox conspired to lose the World Series. Club owners then hired Judge Kenesaw Mountain Landis as the first baseball commissioner (1920-44) and charged him with resolving the crisis. Landis banned eight members of the “Black Sox” for life (despite their acquittal in a court of law), helping to lift suspicion from the professional game.
