From Ohio History Central
This composite photographs shows the 1869 Cincinnati Red Stockings team.
Professional baseball originated in Cincinnati, Ohio. The first game played by a team where all players were professionals and received pay for playing occurred on June 1, 1869, when the Cincinnati Red Stockings defeated the Mansfield Independents, an amateur club. The Red Stockings won by a score of forty-eight to fourteen. The salary for the entire Cincinnati team during the 1869 season was eleven thousand dollars. The Red Stockings went on to win 130 consecutive games during 1869 and early 1870, not losing a game until June 14, 1870. Baseball historians challenge the number of games, because a majority of them involved amateur clubs losing to the Red Stockings. Nevertheless, the club had fifty-seven straight victories against other highly-ranked and professional or semi-professional teams.
The Red Stockings proved to be a leading contender during its first several decades of existence. In 1876, the team, now known as the Cincinnati Reds, became one of the original members of the National League, but this organization expelled the club in 1880 for selling beer at the team’s games. The Reds returned to the National League after a decade’s absence.