Youth: The Politics of YIP

They poured into the vast main concourse of Manhattan's Grand Central Station 3,000 strong, wearing their customary capes, gowns, feathers and beads. They tossed hot cross buns and firecrackers, and floated balloons up toward the celestial blue ceiling. They hummed the cosmic "Ommm," snake-danced to the tune of Have a Marijuana, and proudly unfurled a huge banner emblazoned with a lazy "Y."

The Yippies—1968's version of the hippies—were celebrating spring. Hardly had the equinoctial orgy begun, when it turned as bleak as a midwinter blizzard. A dozen youths scaled the information booth, ripped off the clock hands, scribbled graffiti and...