When Harry Belafonte turned 93 on March 1, he celebrated with a tribute at the Apollo Theater in Harlem, which ended with a thunderous audience singalong to a riff on his star-making 1956 hit, “The Banana Boat Song,” complete with the rapper Doug E. Fresh beatboxing over its famous “Day-O!” refrain.

It was a fitting salute at a building which Mr. Belafonte, in his 2011 memoir, called a “cathedral of spirituality.” But, just a few blocks uptown, he is receiving a quieter but no less momentous celebration.

The Schomburg Center for Research in Black Culture, a division of the New York Public Library, has acquired Mr. Belafonte’s personal archive — a vast maze of photographs, recordings, films, letters, artwork, clipping albums and other materials. It illuminates not just his career as an musician and actor, but as an activist and connector who seemed to know everyone, from Paul Robeson and Marlon Brando to Martin Luther King Jr., the Kennedys and Nelson Mandela.