If you peer closely into the bookstores, salons, and diplomatic circles of the eighteenth-century Atlantic world, Mederic Louis Elie Moreau de Saint-Mery is bound to appear. As a lawyer, philosophe, and Enlightenment polymath, Moreau created and compiled an immense archive that remains a vital window into the social, political, and intellectual fault lines of the Age of Revolutions. But the gilded spines and elegant designs that decorate his archive...