Forty years ago, a few rich kids hatched a nutty idea that became an event that rocked the nation, then morphed into a movement whose legacy lives on. This summer, the young Museum at Bethel Woods in rural New York commemorates the anniversary of that idea, the zeitgeist that spawned it, and the phenomena that flowed from it—all of it evoked in one word: Woodstock.

Recalling his museum’s planning stage, director Wade Lawrence said that “early on, it became clear that the story was more than the three days” at Woodstock. The celebrated Music and Art Fair “was the punctuation point of the decade,” the 1960s, which had begun so hopefully with President Kennedy’s New Frontier and ended in such seeming confusion. The finished museum building, which recalls the round Shaker barns of upstate New York, features films and photo murals that immerse visitors in that roller-coaster period of American history and its epic issues: the clashing cataclysm of the Vietnam War, the watershed Civil Rights acts that set African Americans on the march and Old Southerners to foot-dragging and worse; the complacency of prosperous suburbia that sent teenagers into rebellion.

Visitors begin their journey with an introduction in a 270-degree theater with state-of-the-art audiovisual arrays that replicate the sights and sounds of Woodstock 40 years ago. Afterward they can climb into a “psychedelic bus,” the wildly painted hippie vehicle of choice, sit on the double seats, and view rear-projected videos on the windshield.

The year 1969 was a societal fault line: Richard Nixon was inaugurated, a man walked on the Moon, Elvis Presley made a comeback, the centuries-old Saturday Evening Post folded, bloody Stonewall Inn hatched the gay rights movement, and the first ATM issued cash on Long Island. Warner Brothers released the last Looney Tunes cartoon, PBS launched Sesame Street, Wal-Mart incorporated, Judy Garland died, and Congress reinstated the military draft. In sum, the nation saw sudden ends and sharp beginnings, while people split along political, social, economic, and generational lines, and many thought America had become a powder keg waiting for a match.

So it was symptomatic that the town fathers of tiny Woodstock, New York, quashed a plan for a music festival, fearing it would attract bands of hippies. Undeterred, the four entrepreneurs from New York City found another venue 43 miles away in Bethel and began organizing their al fresco concert on a dairy farm. The event’s original name, “Woodstock,” stuck like thistles.

Though tickets were sold only through record stores and a post office box, thousands flocked toward Max Yasgur’s farm for the opening set on Friday, August 15. Incoming traffic jammed the narrow country roads and closed the New York State Thruway. As more arrived, the surrounding fence was intentionally breached to allow free access for thousands of latecomers who swelled the crowd to perhaps 500,000. Today, the museum displays a piece of that fence as a relic.

Having instantly become one of the largest communities in the state, Woodstock operated as a self-governed commune. Denizens of