Pitchers CC Sabathia and Dellin Betances -- along with G.M. Brian Cashman -- held the ceremony to reveal the "Stonewall Inn" plaque ... which honors the people who fought back during a violent police raid at the Stonewall Inn gay bar in NYC back in 1969.
The incident at the Stonewall is credited with igniting the LGBTQ rights movement.
In fact, the current owners of the Stonewall Inn -- which is still operational in Greenwich Village -- were also on hand for the ceremony.