This is a great story with sound clips! Our thanks to Narratively: Fifty years ago, John Trudell overcame tragedy to become the national voice for Native Americans—and a model for a new generation of activists.

He sat at the same table each evening, sometimes with lighting and sometimes without, a cigarette often in hand, a guest always by his side. In the background, the sound of waves rolling against the rocks and the stuttering of a backup generator were constants. Then, with a crackly yet true radio connection, streaming through the wires from an unthinkable place — Alcatraz Island — he began speaking in a calm, determined voice. The nation was listening.

In the Pacifica Radio Archives, located in a modest brick building in North Hollywood, you can hear what hundreds of thousands of Americans heard on those evenings. File through the cassettes and you will find more than a dozen tapes labeled with a single word: Alcatraz. Each is followed by a date, anywhere from December 1969 to August 1970.

But these were not simply programs about Alcatraz, that island in the notoriously frigid San Francisco Bay that was home to a federal prison until it closed in 1963. Rather, they were broadcast from the former prison building itself, from a small cell without heat and only a lone generator for power rumbling in the background.

The show was called Radio Free Alcatraz, and it was hosted by John Trudell, a Santee Sioux Native American activist and broadcaster.