“Then he talks about what “nature has given” the child, which is not changed by the place of birth ... in all three instances, Vattel places emphasis on the father’s citizenship.”
And that is totally contrary to both English common law and American law.
“So far as we are informed, there is no authority, legislative, executive or judicial, in England or America, which maintains or intimates that the statutes (whether considered as declaratory or as merely prospective) conferring citizenship on foreign-born children of citizens have superseded or restricted, in any respect, the established rule of citizenship by birth within the dominion. Even those authorities in this country, which have gone the farthest towards holding such statutes to be but declaratory of the common law have distinctly recognized and emphatically asserted the citizenship of native-born children of foreign parents.”
Yep. WKA was a native born citizen, which is another way of saying natural born citizen.