In the middle decades of the twentieth century, something unprecedented happened to the American mind. For the first time in human history, an entire nation of nearly two hundred million people began watching the same images, hearing the same stories, and absorbing the same cultural references at the same moment every evening. Television did not merely entertain Americans. It synchronized them, creating a shared national consciousness that had never existed before and may never exist again. Before television, American culture was radically fragmented by geography, ethnicity, religion, and class. A farmer in Nebraska and a factory worker in Brooklyn inhabited almost entirely separate cultural worlds, reading different newspapers, listening to different radio programs, and sharing few common reference points beyond the broadest national events. Telev ...