The natives, or natural-born citizens, are those born in the country, of parents who are citizens.
The modern usage however has native born merely born in the country, but "natural born" retains it's original meaning, except for after-birthers, who thinks it's meaning morphed along with that of "native". And that might be true for casual purposes, but for Constitutional purposes, it retains it's 1787 meaning.
The original uses indigenous, not NBC.
Its use as such existed BEFORE Vattel lived:
164050; < L indigen(a) native, original inhabitant (indi-, by-form of in- in-2 (cf. indagate) + -gena, deriv. from base of gignere to bring into being; cf. genital, genitor) + -ous
Also: Synonyms 1. autochthonous, aboriginal, natural.
No one cares, or should care, what the modern usage is. And Vattel is nice, but he wrote in French. Word for word translations of terms of art might be interesting, but that's all.
We're talking late 18th century English here and the definitive reference for that and the entire history of English word usage is the Oxford English Dictionary. The entry for natural-born there makes it pretty clear that a natural-born subject did not have to be born in England, but only that his parents had to be English subjects.
ML/NJ