David Nolan, a former Colorado resident who founded the Libertarian Party, died over the weekend in Tucson, Arizona, either from a stroke or heart attack while driving his car, writes The New York Times.

The 66-year-old opposed the Vietnam War and President Richard Nixon’s meddling in the free market, both of which inspired him in 1971 to create the Libertarian Party. Nolan devised a well-known graph called the Nolan Chart, which maps how much people desire economic freedom and personal freedom. Libertarians support the greatest amount of freedom for both. Nolan was among the candidates running for U.S. Senate in Arizona, although Republican John McCain easily won reelection. Legend has it that the Libertarian Party was born in Nolan’s Westminster living room on December 11, 1971, but in fact it began at another early party member’s home in Colorado Springs. Still, the ideas for creating the party came months earlier during a meeting at Nolan’s abode.

David Weigel recalls meeting Nolan in 2008 while covering the Libertarian Party convention in Denver for Reason magazine. “It’s unusually difficult to say what Nolan’s legacy will be,” Weigel writes for Slate. “He leaves behind a small ‘l’ libertarian movement that is more powerful, with greater control over the levers of the GOP and more footing in popular culture, than at any time in living memory. (Witness the current, libertarian-driven backlash against the TSA if you want proof.) He also leaves behind a Libertarian Party that, like almost every third party in American history, struggles for relevance and has its best ideas co-opted by major-party politicians who go on to disappoint their supporters. But if the measure of an activist’s success is bringing attention to his ideas, and bringing them from the fringe of respectability to the center, David Nolan was a success.”