The Second Vatican Council enacted the most sweeping changes the Catholic Church had seen in centuries. In the United States, it launched a war--a series of cultural clashes that Mark Massa calls the ''Catholic Sixties.'' The first stirrings of upheaval took place in the pews. Changes to the mass were felt immediately and viscerally by the faithful. Suddenly, one Sunday, the mass as they had always known it was different, and so was the Church they had believed was timeless and unchanging. Once the Church opened the door to change, Massa argues, it could not be closed again. Skirmishes broke out over the proper way to worship. Soon, Catholics were bitterly divided over birth control, abortion, celibacy, female priests, and the authority of the Church itself. These battles were waged within the Church, but they mirrored and shaped the larger conflicts in American society. In readable and compelling prose, Massa tells the story of Vatican II and the culture war it ignited--a war that is still being waged as fiercely as ever.