Long before the United States was any more than a collection of British colonies in North America, Protestants viewed Catholicism as a threat to national identity, individual liberty, personal salvation, and the stability of free government. Their fears continued up through the presidential campaign of John F. Kennedy. Understanding why Protestants viewed Catholicism with fear and loathing reveals much about the evolution of American understandings of freedom, which for decades were forged unabashedly in opposition to the Catholic Church and its understanding of what freedom was and how people could attain it. To be sure, social issues like birth control and gay marriage have helped to create a “new ecumenism.” Just as important, however, have been the inequities caused by the advent of modern industrial capitalism, which have forced American Protestants to stop using the Catholic Church as a foil when defining freedom and the conditions that sustain it.