“You can’t stay seventeen forever,” one teenager advises another in George Lucas’s vivid recollection of the summer of 1962. Nonetheless, American Graffiti preserves the end of innocence in an amber glow. As the film cruises through one long night in small-town Northern California, from dusk at Mel’s Drive-In to dawn over the golden Central Valley, it surveys the teen social taxonomy of college-bound boys and gang members, good girls and greasers, all facing the end of summer and the beginning of the rest of their lives. Like nostalgia itself, this boomer touchstone—Lucas’s second feature with Francis Ford Coppola as producer—is both specific and eternal.