This chapter focuses on the American Revolution of 1775–1783, which often appears as the first cause célèbre in the subsequent literature on the law of civil war. Studying closely the legal documents and case law during the revolution, it argues that the revolution of the thirteen colonies displayed a typical structure of transatlantic civil wars that was common with the early modern civil wars of Chapter 1 as well as the subsequent transatlantic revolutions. Its key features include the early emergence of an insurgent prize jurisdiction, the diplomatic disputes caused by the imperial counter-revolutionary responses, the question of foreign intervention, and ultimately the connection between sovereignty and state responsibility. It also links these phenomena with the rise of international arbitration as an essential technique of post-revolutionary settlements in the classical law of nations.