From its earliest days, America was a home for spiritual seekers. In 1694, the religious tolerance of the Pennsylvania Colony enticed a Transylvanian monk and his forty followers to cross the Atlantic. Almost two hundred years later, a charismatic preacher founded a utopian community in Oneida, New York, that practiced socialism and free love. In the 1960s and '70s, a new generation of seekers gathered in vegetarian restaurants in Los Angeles, Satanic...