Hollywood souvenir shop postcards of Southern California, Mid-20th century: beach-movie dreamgirls, endless orange groves, extinct amusement parks, and those amazing freeways flowing out from L.A. like glorious rushing rivers-or sinister, smoggy tentacles, depending on your point of view. Each bulbous car on the interchange is a droplet in the multi-generational flood of dreamers, go-getters, black sheep, and miscellaneous drifters who poured into...