Was The Louisiana Purchase Unconstitutional? IV

After all of this build up, the Constitutional analysis is a let down – with all due respect to Thomas Jefferson, these are not close questions. Let’s plow ahead anyway, starting with Representative Nicholson’s first issue: did the Constitution bar the United States from acquiring, by treaty, sovereignty over new territory, i.e., territory that it did not possess in 1789?

The proponents of unconstitutionality apparently grounded their conclusion in the idea that the “United States” referred to in the Constitution was and could only be the physical entity as it existed in 1789. New Hampshire Federalist Senator William Plumer, for example, apparently believed that the reference in the Preamble "to ourselves and our Posterity" suggested that the Constitution was limited to the geographic confines that existed upon ratification:

The constitution of the United States was formed for the express purpose of governing the people who then & thereafter should live within the limits of the United States as then known & established. It never contemplated the accession of a foreign people, or the extension of territory.

As David Currie has noted, "If that was the best opponents of acquisition could do, it was pretty poor." Article II, Section 2 says simply that the President "shall have Power, by and with the Advice and Consent of the Senate, to make Treaties, provided two thirds of the Senators present concur." Why isn’t that the beginning and end of the matter? Transfer of territory has been a common subject of treaties for thousands of years. Nothing in Section 2 suggests that that subject is somehow carved out from the treaty power. To the contrary, the language is general and admits of no exceptions.