This Article argues, contrary to conventional accounts, that the animating purpose of the American Constitution was to facilitate the admission of the new nation into the European-centered community of “civilized states.” Achieving international recognition—which entailed legal and practical acceptance on an equal footing—was a major aspiration of the founding generation from 1776 through at least the Washington administration in the 1790s, and constitution-making was a key means of realizing that goal. Their experience under the Articles of Confederation led many Americans to conclude that adherence to treaties and the law of nations was a prerequisite to full recognition but that popular sovereignty, at least as it had been exercised at the state level, threatened to derail the nation’s prospects. When designing the Federal Constitution, the framers therefore innovated upon republicanism in a way that balanced their dual commitments to popular sovereignty and earning international respect. The result was a novel and systematic set of constitutional devices designed to ensure that the nation would comply with treaties and the law of nations. These devices, which generally sought to insulate officials responsible for ensuring compliance with the law of nations from popular politics, also signaled to foreign governments the seriousness of the nation’s commitment. At the same time, however, the framers recognized that the participation of the most popular branch in some contexts—most importantly, with respect to the question of war or peace—would be the most effective mechanism for both safeguarding the interests of the people and achieving the Enlightenment aims of the law of nations. After ratification, the founding generation continued to construct the Constitution with an eye toward earning and retaining international recognition, while avoiding the ever-present prospect of war. This anxious and cosmopolitan context is absent from modern understandings of American constitution-making.