Late-eighteenth-and nineteenth-century American texts abound with representations of Catholic malevolence. But rather than simply indicating authorial bias against Catholic practitioners, these representations reveal anti-Catholicism's fundamental importance to the U.S.'s emerging liberal democratic tradition. Catholicism stands in texts of this period at the intersection of the religious and the national, as writers across decades and genres struggle to reconcile liberal democracy's promises of egalitarianism and tolerance with Catholicism's ostensibly tyrannical hierarchy and dogmatism. Thus in addition to demarcating a religious identity and set of theological practices, Catholicism has long operated as a test case for the efficacy of liberal democratic notions of privacy, pluralism, and equality. Excavation of U.S. liberal democracy's religious roots illuminates the ways in which that political tradition has aligned the nation with Protestantism and thereby ensured the mutual dependence, rather than the "separation" we so often take for granted, of church and state. From the earliest writings of the Continental Congress to the late-nineteenth-century novels of Mark Twain, U.S. discourses of freedom and self-governance construct Catholics as political subjects aiming, as John Jay put it, to "reduce the ancient free Protestant Colonies to the same state of slavery with themselves." Significantly, the drama of Protestant-Catholic conflict often played itself out when Anglo-Protestant writers considered the U.S.'s place within the American hemisphere. Thus the passage of the 1774 Quebec Bill inspired contemporary discourses of religious privacy (chapter one); debates over U.S. expansion into western and especially Mexican territories produced discussions of pluralism and representational governance (chapters two and three); and mid-century contemplations if Haitian Catholicism (chapter four) forced many U.S. citizens to confront liberal democracy's failure to adequately address the fact of racial as well as religious difference within the nation. In its insistence that U.S. political culture cannot be understood apart from anti-Catholicism, this dissertation demonstrates that, in their efforts to construct a religiously free public sphere, proponents of liberal democracy have over time rehearsed a discourse that fuses nation and religion.