This chapter explores Carlo Sigonio’s long-term impact by zooming in on the nascent United States of America. It shows that Sigonio was seen as a leading comparative constitutional historian and one of the most cited authorities that would-be reformers turned to in the intense debate on the reform of the British imperial constitution in the second half of the eighteenth century. His analyses of the Roman Empire yielded timeless lessons for metropolitan and colonial administrators alike. Most importantly, Sigonio structured his studies of Roman, Athenian, Hebrew, and medieval Italian laws and customs in a way that revealed these complex historical states’ constitutional essence, making comparative analysis possible. This chapter shows why American lawyers, British politicians, and merchants and soldiers with a true British–American identity, explicitly drew on Sigonio’s analysis of Roman colonization in several reform plans for the British Empire, with particular attention to the American colonies.
