>>...Vattel had nothing to do with US law on citizenship...<<
True, but either way, de Vattel’s definition (swiss, french or otherwise) was wholly consistent with the commonly accepted definition of the term, “natural-born-citizen” at the time of the Constitution’s writing, was it not? That deVattel’s writing were considered a reference work provides us with a codifed definition. And to be sure, I have yet to hear of any other inconsistent definition from the period. Have you?
“True, but either way, de Vattel’s definition (swiss, french or otherwise) was wholly consistent with the commonly accepted definition of the term, “natural-born-citizen” at the time of the Constitution’s writing, was it not?”
No, it was not. The phrase ‘natural born subject’ had a well established meaning and was found in most of the colonial laws involving citizenship. With Independence, the new states modified their laws to replace subject with citizen, making the phrase NBC a known legal term PRIOR to the Constitution.
That known legal meaning including everyone born in the jurisdiction a NBC, except the children of ambassadors and invading armies.