ABSTRACT
The term most often used to describe law in diplomacy during the early modern era is the “law of nations.” Scholars generally approach this law via a series of treatises, published in northern Europe during the seventeenth and eighteenth centuries by philosophers such as Hugo Grotius, Samuel von Pufendorf, and Emerich de Vattel. Treatises of this kind were important to American revolutionaries, who leaned on them for insight into European legal norms, and historians often assume, consequently, that they must have governed the conduct of early modern diplomacy. Scholars have given scant attention to customary law to date—in part because it was unwritten and is hard to access, and in part because it was enforced in ways that runs counter to modern legal ideals. The American Revolution threatened that detente. The Americans claimed title to the trans-Appalachian west, and with it navigation rights on the Mississippi River and into the Gulf of Mexico.
