Now, thanks to a quirk of fate, some of his most stirring words are getting a whole new hearing, as CBS News correspondent Michelle Miller reports.
The halls of the University of Dayton field house echoed with the voice of Martin Luther King, Jr. The November 1964 speech was powerful and passionate in its optimism.
"I must say that we have come a long, long way in the struggle to make civil rights a reality," King said that day.
King was in Dayton, Ohio to raise funds for his civil rights agenda.
Click here to read more about the rediscovery of the recording and to listen to audio of Dr. Martin Luther King, Jr.'s 1964 speech at the Universty of Dayton.
Ted Clark was 28 at the time and was one of the few whites in attendance. He remembers exactly where he sat.
"I have to admit there was some apprehension," Clark said.
During the 1960s, Dayton, like so many American cities, was caught up in the struggle for racial and economic equality.
"Where do we see it? We see it in housing, I imagine you have some residential areas here in Dayton," King said to applause in his speech.
"I am convinced today that segregation is on its deathbed," he said.
"You could just feel the electricity in this place it was unbelievable," Clark said.
Over time the recording of King's Dayton speech had been forgotten, until Dayton professor emeritus Herb Martin stumbled across it.
"I was gonna tape over it, but luckily fate kept me from doing that," Martin said.
Martin collected old reels to re-record his performances of poet Paul Lawrence Dunbar - a hobby that inspired a documentary by independent filmmaker David Schock.
That's how Schock and Martin came to hear the King speech.
"You think, 'Wow, this is really something of value,'" Martin said.
45 years later, Dayton has changed, but Clark believes there is still progress to be made.
Friends of mine, they have racially tinged attitudes. So yes, it's out there," he said.
To further that goal, Martin has donated the tape to the university archives, giving a piece of newly discovered history, a second chance to be heard.