In this book, James Lewis demonstrates the centrality of Americanideas about and concern for the union of the states in thepolicymaking of the early republic. For four decades after thenation's founding in the 1780s, he says, this focus on securing aunion operated to blur the line between foreign policies anddomestic concerns. Such leading policymakers as Thomas Jefferson, James Madison, James Monroe, John Quincy Adams, and Henry Clay worried about the challenges to the goals of the Revolution that would arise from a hostile neighborhood--whether composed of new nations outside the union or the existing states following a division of the union. At the center of Lewis's story is the American response tothe dissolution of Spain's empire in the New World, from thetransfer of Louisiana to France in 1800 to the independence ofSpain's mainland colonies in the 1820s. The breakup of theSpanish empire, he argues, presented a series of crises for theunionist logic of American policymakers, leading them, finally, to abandon a crucial element of the distinctly American approachto international relations embodied in their own federal union.