This chapter provides an outline of the mainstream of the liberal consensus, particularly as related to the seminal thought of Thomas Jefferson, while giving some consideration to its main challengers. Jeffersonian liberalism is absolutely central to nineteenth-century American thought and politics. The chapter examines the legacy of Andrew Jackson and his followers. Ralph Waldo Emerson's intense individualism and admiration for great men arguably could underlie a regime of competitive capitalism, yet his intense moral commitments make him a real prophet of the progressive tradition. The pro-slavery arguments are the antithesis of the anti-slavery position. The anti-slavery argument reached its moral and rhetorical climax in the thought and practice of Abraham Lincoln who combined theoretical analysis and political skill needed to bring an end to slavery. He achieved a powerful synthesis of most of the major lines of American political thought that had preceded him.