The Dictionary of Early American Philosophers, which contains over 400 entries by nearly 300 authors, provides an account of philosophical thought in the United States and Canada between 1600 and 1860. The label of "philosopher" has been broadly applied in this Dictionary to intellectuals who have made philosophical contributions regardless of academic career or professional title. Most figures were not academic philosophers, as few such positions existed then, but they did work on philosophical issues and explored philosophical questions involved in such fields as pedagogy, rhetoric, the arts, history, politics, economics, sociology, psychology, medicine, anthropology, religion, metaphysics, and the natural sciences. Each entry begins with biographical and career information, and continues with a discussion of the subject's writings, teaching, and thought. A cross-referencing system refers the reader to other entries. The concluding bibliography lists significant publications by the subject, posthumous editions and collected works, and further reading about the subject.

In a powerful challenge to conventional wisdom, Philip Hamburger argues that the separation of church and state has no historical foundation in the First Amendment. The detailed evidence assembled here shows that eighteenth-century Americans almost never invoked this principle. Although Thomas Jefferson and others retrospectively claimed that the First Amendment separated church and state, separation became part of American constitutional law only much later. Hamburger shows that separation became a constitutional freedom largely through fear and prejudice. Jefferson supported separation out of hostility to the Federalist clergy of New England. Nativist Protestants (ranging from nineteenth-century Know Nothings to twentieth-century members of the K.K.K.) adopted the principle of separation to restrict the role of Catholics in public life. Gradually, these Protestants were joined by theologically liberal, anti-Christian secularists, who hoped that separation would limit Christianity and all other distinct religions. Eventually, a wide range of men and women called for separation. Almost all of these Americans feared ecclesiastical authority, particularly that of the Catholic Church, and, in response to their fears, they increasingly perceived religious liberty to require a separation of church from state. American religious liberty was thus redefined and even transformed. In the process, the First Amendment was often used as an instrument of intolerance and discrimination.

Offers a series of fresh perspectives on America's encounter with Catholicism in the nineteenth-century. While religious and immigration historians have construed this history in univocal terms, Jon Gjerde bridges sectarian divides by presenting Protestants and Catholics in conversation with each other. In so doing, Gjerde reveals the ways in which America's encounter with Catholicism was much more than a story about American nativism. Nineteenth-century religious debates raised questions about the fundamental underpinnings of the American state and society: the shape of the antebellum market economy, gender roles in the American family, and the place of slavery were only a few of the issues engaged by Protestants and Catholics in a lively and enduring dialectic. While the question of the place of Catholics in America was left unresolved, the very debates surrounding this question generated multiple conceptions of American pluralism and American national identity.