Robert Nozick worked in a Lockean tradition of political philosophy, a tradition with deep resonance in the American political culture. This paper attempts to explore the formative moments of that culture and at the same time to clarify the role of Lockean philosophy in the American Revolution. One of the currently dominant approaches to the revolution emphasizes the colonists' commitments to their rights, but identifies the relevant rights as “the rights of Englishmen,” not natural rights in the Lockean mode. This approach misses, however, the way the Americans construed their positive or constitutional rights in the light of a Lockean background theory. In a word, the Americans recreated an amalgam of traditional constitutional principles and Lockean philosophy, an amalgam that nearly guaranteed that they and the British would speak past each other. The ambiguities and uncertainties of the British constitution as extended to the colonies provided an incentive to the Americans (but not the British) to look to Locke as a guide to their rights, thereby helping win a place for Lockean theory in American political thinking.