An icon of the anti-establishment protest movement for years, Hayden later became a politician. He made an unsuccessful bid for a Senate seat in 1976, and was later elected to the California state Legislature, where he served for 18 years. He was also an author, publishing books about the Chicago Seven (originally the Chicago Eight, until one defendant had his trial severed) as well as political manifestos and memoirs.
In 1993, Hayden spoke to NPR about the tensions on the streets of Chicago in 1968, and the violence between police and protesters at the Democratic National Convention that led to his trial.
"By 1968, the Vietnam War was claiming tens of thousands of lives, Indo-Chinese and American," he said in that interview. "The Democratic Party was running the country, and so you had a bipartisan Democratic and Republican war policy that seemed to be escalating without end ... the Democratic Party was controlled from the top by traditional bosses who chose their nominees and their parties platforms in smoke-filled rooms. And so the goal of the protest was not only to protest the war, but to protest the disenfranchisement that was so deep. Here we were, if you were 18, you could be drafted and sent to war, but you couldn't vote for Eugene McCarthy."
He said some things had improved in America over the course of 25 years, but that the country had far to go:
"I would hope that we learned something about how to deal with dissent and protest — that having an inclusive process where you open the doors is a lot better than sending in the police. ... What was not learned, however, is the lesson that prevention and getting ahead of our problems is uppermost.
"We still disenfranchise racial minorities in economic terms. Young people still feel they're not listened to. ... I think the environmental issue has begun to eclipse everything else because our population has doubled and the resources of the world have been cut in half since I was born and there's very little focus on those issues on the political agenda.
"So I don't know on the balance sheet whether to mark myself as an optimist or pessimist, but we've got to go on."
Go on he did — serving several more years in office and writing more than a dozen other books. He faced censure from some on the left who accused him of joining the same establishment he once criticized, as well as those on the right who objected to his protests in the '60s.
But as the decades passed, Hayden remained a prominent voice on progressive causes, including environmental issues, economic policy and continued anti-war efforts.
More recently, he surprised some in progressive circles by supporting Hillary Clinton over Bernie Sanders in this year's Democratic primary.
"Bernie and I only have one thing in common you need to know: We're both politicians, so we make decisions based on what's possible," he told NPR this summer. "I've really been trying to work towards a goal that seems to be getting realized, and that's a serious united front against Trump."
Copyright 2016 NPR. To see more, visit http://www.npr.org/.