This essay examines the relations between state formation, capitalism, and slavery in North America from the early eighteenth century through the post-Civil War era. By examining a series of case studies involving important policies, wars, and crises that occurred during this 150 year period, the essay argues that we must simultaneously consider the process of state formation and the rise of a capitalist economy that very much involved slavery. Recent distinct scholarly literatures have argued for a much stronger and more powerful U.S. nation state, and for understanding slavery as the core of American capitalism. This essay, by calling for a social history of federalism, argues that we must think about the strengths and weaknesses of the U.S. nation-state, and the compatibilities but also major differences between free and slave labor regimes and political economies. This essay seeks to bring more precision to our discussion of the nation-state in the early American republic by asking what conditions allowed it to act with real coercive authority, when it could do so, why it could do so, and just as importantly, when and why it could not. The possibilities and limits for state power had a profound impact on the growth and development of the North American slave political economy, and on its thorough interconnectedness with continental, indeed global, capitalism. It was this very interconnectedness that produced the hegemonic breakdown and the disintegration of the national polity and nation-state in civil war.