* The founding fathers weren’t citing Vattel, or else they would have used any of several different terms used to translate Vattel into English (”natives,” where “les indigens” would have connoted a primitive people), or left “les naturels” as a term of art, as Franklin’s copies did.
* Vattel writes several things which are contrary to the founding fathers’ concepts of natural law. In fact, Vattel’s work, as a whole, would have been an excellent rebuttal to the Declaration of Independence.
* Vattel failed to consider what became commonplace in the US immediately: immigrants from different nationalities. Under Vattel’s definitions, such a person would be defined as having no homeland. Such a situation would be considered abominable by the Natural Law authors the founding fathers do cite.
* You insist Vattel was commonly taught in US universities at the time of the founding. Which ones? There were precious few. Or is this based, as I have seen several NBC activists do, on misreading Marshall’s assertion that “When we avert to the course of reading generally pursued by American statesmen in early life, we must suppose that the founders of the Constitution were intimately acquainted with those wise and learned men, whose treaties on the law of nature and nations have guided public opinion on the subject of obligation and contract”? Given the relative newness of Vattel’s work, this almost certainly refers, instead, to Locke, Montesquieu, Coke, Blackstone, Aquinas, and Hobbs. Indeed, these authors are all directly cited, unlike Vattel. Any echo of Vattel probably comes from his intellectual sire, Wolff. Keep in mind that when Franklin gushes to Vattel’s editor, he is receiving a gift from as a diplomat.
In his (David Ramsay) 1789 essay, while not using the phrase natural born Citizen, Ramsay described the original citizens that existed during the Founding and what it meant to acquire citizenship by birthright after the Founding. The Constitution itself shows that the Framers called the original citizens Citizens of the United States and those that followed them natural born Citizens. He said concerning the children born after the declaration of independence, [c]itizenship is the inheritance of the children of those who have taken part in the late revolution; but this is confined exclusively to the children of those who were themselves citizens
. Id. at 6. He added that citizenship by inheritance belongs to none but the children of those Americans, who, having survived the declaration of independence, acquired that adventitious character in their own right, and transmitted it to their offspring
. Id. at 7. He continued that citizenship as a natural right, belongs to none but those who have been born of citizens since the 4th of July, 1776
. Id. at 6. Ramsay did not use the clause natural born Citizen. Rather, he referred to citizenship as a birthright which he said was a natural right. But there is little doubt that how he defined birthright citizenship meant the same as "natural born Citizen," "native," and "indigenous," all terms that were then used interchangeably.