It's not clear that Sanders ever considered himself one of the hippies, though he was described in a 2007 New York Times Magazine profile as "a humorless aging hippie peacenik Socialist from Brooklyn."
But Sanders did fit the mold of the counterculture. He led protests at the University of Chicago against racially segregated campus housing and opposed the Vietnam War. He told the New York Times he moved to Vermont because he had always been "captivated by rural life." He worked there as a carpenter, filmmaker and writer and became a member of socialist Liberty Union Party.
By the mid-'70s, the hippie-dom faded, but many who had moved there settled down, including Sanders. Amanda Gustin, public program coordinator for the historical society, told the Associated Press the hippie migration left a lasting mark on state politics, with those who remained becoming involved in local government.
"I think there's something to be said for sort of the more progressive wing of politics getting its start in Vermont in the 1970s," she said.
Sanders lost five statewide races before winning the Burlington mayoral race in 1981 -- by 10 votes against a Democrat who didn't bother to campaign because he thought he had the election in the bag.
Sanders said there was "a lot of fear in the beginning" about him being socialist, but that subsided over his first term. "We have not transformed the world. Much of what we do is not radical," he told the Associated Press at the time.
His city hall office was decorated with a poster of Eugene V. Debs, who ran for president on the Socialist Party ticket from the 1900s to 1920s. U.S. News & World Report named Sanders one of America's 20 best mayor in 1988. He was mayor until 1989, and was elected to the U.S. House in 1991.
"I am a socialist, of course I am a socialist," he told a Democratic opponent in a mayoral debate, according to an Associated Press story in 1983. "To hold a vision that society can be fundamentally different, to believe that all people can be equal, that is not a new idea. ... I don't think there is an administration in the country that is more progressive than this one."
The hippies have grown up, and one of their own is running for the White House.