A commemorative Negro Leagues baseball stamp, depicting a player sliding safely into home plate, was unveiled by the U.S. Postal Service at Northeastern’s John D O’Bryant African-American Institute on Thursday, part of a series of events and programs connected to the University’s ongoing art exhibit on the historic leagues.

The exhibition at Gallery 360— “Shades of Greatness: The Art of Negro Leagues Baseball” — includes 35 paintings, photographs, etchings, three-dimensional installations and signs created by local and national artists, and closes on Friday.

Over the past two months, Northeastern has collaborated with the Boston Red Sox and the Boston Foundation to enhance the understanding of social issues and awareness of the contributions of Negro Leagues baseball players. Northeastern’s Office of Institutional Diversity and Equity worked to bring the exhibit to Northeastern.

Partners in the exhibit as well as special guests from the Negro League Baseball Museum and the United States Postal Service praised its artistic, historical and intellectual value.

“The exhibit has sparked an intellectual dialogue on sport and race in the community,” said Dr. Raymond Doswell, the Negro League Baseball Museum’s vice president for curatorial services. “It doesn’t matter who hit the most home runs or stole the most bases; what’s important is understanding why these players participated in a game despite what was happening to them.”

Susan Goodenow, senior vice president for public affairs and marketing for the Boston Red Sox, added, “It’s important to share the history and tell of the contributions that Negro League players and teams made to our national pastime.”

She said groups of children from Major League Baseball’s Reviving Baseball in Inner Cities program have visited the exhibit since its opening in mid-May.

Andrea Martinez, a program associate for the Boston Foundation, called the chance to work with Northeastern, “an opportunity too good to pass up,” noting that the exhibit has sparked significant interest among the foundation’s donors.

The Negro Leagues were the perfect subject to depict on a new stamp, added Boston Postmaster James Holland. “Only subjects or events with widespread, national appeal make it,” he said.

Former Red Sox players Dennis “Oil Can” Boyd and Sam Horn were among those in attendance at the event.

A quartet, led by Northeastern music professor Leonard Brown and African-American studies chair Emmett Price, opened the event with the traditional Negro National Anthem, “Lift Every Voice and Sing.”