The early years of Cincinnati professional baseball were as robust and capricious as the Industrial Revolution America was involved in at the time.
The city’s first professional team, the Red Stockings, was also the first entirely professional baseball team in the nation. The Stockings established a rich baseball legacy for Cincinnati with their undefeated 1869 debut season, which remains the only undefeated season in professional baseball history. However, the promising start didn't keep the team together, as two years later the majority of the roster transferred to Boston’s Red Stockings.
With the inception of the National League in 1876, Cincinnati fielded another iteration of the Red Stockings—then known as the Cincinnati Red Stockings—and became a charter member of the league. Yet four years later when the team president rejected a league pledge to keep ballparks closed on Sundays and ban beer, Cincinnati was thrown out of the league. To spite the National League, the very next year Cincinnati joined new, rival league, American Association, where it would play for nine seasons and win the 1882 league pennant before rejoining the National League for good.