Understood, and Vattels writing is not "French law"
The US Constitution and US laws in general are based rather in common law, an almost entirely separate code based on centuries of English judicial decisions.
Not sure that is true.
While in general it may be true, I'm CERTAIN that it is not true with respect to citizenship, a concept that the English were bereft of in 1775. The Framers were quite explicit on the subject.