Although contemporary Americans take it for granted that a “constitution” is a written document, written constitutions were almost unprecedented at America's founding. James Wilson, one of the most significant yet overlooked of America's founders, offers a comprehensive theory of America's written constitution. Wilson argues that the written-ness of the U.S. Constitution serves two essential functions. As an initial matter, it memorializes the primacy of liberty by announcing that the authority of government derives only from a free people. Perhaps more importantly, however, the written constitution uplifts and refines the character of its citizens, and thus helps to constitute a people. A review of Wilson's writings and speeches reveals how, even in a rights-centric political order, the written constitution helps to cultivate moderate and civic-minded citizens without diminishing the fundamental importance of individual rights.