The game that most closely resembles modern-day baseball originated in New York City. Historians note that similar games were played in Philadelphia and Massachusetts, but the Knickerbocker Baseball Club of New York City is credited with establishing the earliest rules of the modern game in 1845.
The earliest recorded game using the Knickerbocker rules took place in 1846, in Hoboken, N.J. Some of the Knickerbocker rules that are still used today include the establishment of foul territory and the requirement that runners stay in the base path. The first professional, salaried team was the Cincinnati Red Stockings, established in 1869.