A long-lost audio recording of a 50-year-old speech delivered at UCLA by the late civil rights leader Martin Luther King Jr. has been unearthed in a storage room in the communication studies department, which will put it online. The 55-minute speech (embedded below) will go live today on King’s birthday, four days before the national holiday honoring him.

“It’s a speech of importance that deserves to be released on a day of importance,” said Derek Bolin, a 2013 UCLA graduate who found the recording while working as a contract archivist. Over the years, King’s visit to UCLA became a proud part of campus lore. The spot where the civil rights leader stood to deliver his speech, at the base of Janss Steps, is now marked with a plaque and is a stopping point on some campus tours.

The speech, recorded originally on 7-inch, reel- to-reel tapes, will become part of the UCLA Communication Studies Speech Archive, an online collection of more than 400 speeches delivered on campus by politicians, activists, entertainment personalities and other newsmakers primarily during the 1960s and ’70s. Like King, the speakers were brought to campus by UCLA's now-defunct Associated Students Speakers Program. With donations from alumni, the department began last year to digitizethe speeches and upload them to YouTube. So far, more than 180,000 listeners have tapped into the online archive.