The Constitution is based on popular sovereignty. But who are the People? Two hundred and twenty six years after the ratification of the Constitution, the answer to this question is still debated. This Note jumps into the fray, closely examining the Constitution itself and the history surrounding its adoption in order to reverse-engineer a coherent theory of American popular sovereignty as it was understood at the time of ratification and the adoption of the Bill of Rights. Did the state peoples exist as sovereigns before the Constitution? If yes, did the Constitution consolidate them into one unitary national people? If not, is there a national people in addition to the state peoples? In short, there is a national people, but it coexists with the sovereign state peoples. Furthermore, the national people must be interpreted through a lens of state peoples—the People is national in scope and importance, but it is defined in reference to the state peoples. The reservoir of reserved powers—those uses of governmental authority that are not expressly mentioned in the text of the Constitution—defaults to the state level. This balance of peoples means that the American system is one of limited sovereignty. Neither the federal nor the state governments can eliminate or alter the other; they reinforce each other in a structure that presupposes its perpetuity. Dual popular sovereignty is the essence of federalism, and it has broad implications for the fundamental distribution of power between the federal government and the states.