Sam Haselby offers a new and persuasive account of the role of religion in the formation of American nationality. The book shows how, in the early American republic, a contest within Protestantism reshaped American political culture, leading to the creation of an enduring religious nationalism.

Following U.S. independence, the new republic faced vital challenges, including a vast and unique continental colonization project undertaken without (in the centuries-old European senses of the terms) either "a church" or "a state." Amid this crisis, two distinct Protestant movements arose: one, a popular and rambunctious frontier revivalism, and the other a nationalist, corporate missionary movement dominated by New England and Northeastern elites. The former heralded the birth of popular American Protestantism, while the latter marked the advent of systematic Protestant missionary activity in the West.

The world-historic economic and territorial growth that accelerated in the early American republic, and the complexity of its political life, gave both movements unusual opportunity for innovation and influence. The Origins of American Religious Nationalism explores the competition between them in relation to major contemporary political developments. More specifically, political democratization, large-scale immigration and unruly migration, fears of political disintegration, the rise of American capitalism and American slavery, and the need to nationalize the frontier, all shaped, and were shaped by, this contest. The book follows these developments, focusing mostly on religion and the frontier, from before the American Revolution to the rise of Andrew Jackson.

The approach helps explain many important general developments in American history, including why Indian removal took place when and how it did, why the political power of the Southern planter class could be sustained, and, above all, how Andrew Jackson was able to create the first full-blown expression of American religious nationalism.