You want to argue that "chose to adopt many selected principles of law contrary to English/British precedents and consistent with international practices." Fine. Then why didn't the Founders define "natural-born citizen" in the Constitution? Why didn't they instead say
You can't say it's obvious that a reasonable person would've used de Vattel's definition if until 1783, all reasonable persons in the nascent United States were "natural-born subjects" of the British Crown and understood that "children born to alien parents in England [were] natural born English citizens."
"Natural-born citizen" isn't defined in the Constitution. As Chief Justice Waite noted in Minor, resort must be had "elsewhere" to find out, and Chief Justice Waite resorted to (English) common law, not de Vattel.
It was true in England-Great Britain only because the sovereign, the King/Queen, commanded it to be so. In the domains of other states, the sovereign did not command it to be so. Consequently, a child whose father was a foreigner and was born in those domains was NOT commanded to owe allegiance at birth to the sovereign of the domain in which the birth occurred. In those domains the child was the natural born citizen of the state to whom the father owed permanent allegiance to its sovereign.
You want to argue that "chose to adopt many selected principles of law contrary to English/British precedents and consistent with international practices." Fine. Then why didn't the Founders define "natural-born citizen" in the Constitution? Why didn't they instead say
No person except a natural born Citizen, that is, born to two citizen parents, or a Citizen of the United States, at the time of the Adoption of this Constitution, shall be eligible to the Office of President...
You can't say it's obvious that a reasonable person would've used de Vattel's definition if until 1783, all reasonable persons in the nascent United States were "natural-born subjects" of the British Crown and understood that "children born to alien parents in England [were] natural born English citizens." "Natural-born citizen" isn't defined in the Constitution. As Chief Justice Waite noted in Minor, resort must be had "elsewhere" to find out, and Chief Justice Waite resorted to (English) common law, not de Vattel.
On the contrary, I can do so. It was a very easily undrstood concept in that day and age, even for the people who could not read or write. People understood the concept of loyalty and allegiance, in part, because the failure to respect the demands for loyalty and allegiance resulted in catastrophic and personal consequences. It was easy to understand who was and who was not a natural born subject by simply looking to whom the child and the child's father owed allegiance at the time of the child's birth.
If the child's father owed allegiance to the King of France and/or the French Republic, and the child was born in the domains of the King or Queen of England or Great Britain, the child was regarded by England or Great Britain as a natural born English or British citizen for life without possibility of expatriation while in England or Great Britain, its other domains, or on the High Seas. The same child was regarded by France as a natural born French citizen while in the domains of France, other sates, or the High Seas.
Consequently, the competing and exclusive claims upon the natural born citizenship of the child led to unreconciled conflicts and disputes over the question of to whom the child owed allegiance. U.S. citizens had an acute understanding of these problems because of the consequences they suffered every time the sovereigns quarreled and waged war in North America and on the High Seas during the French & Indian Wars, the American Revoultionary War, the French Quasi-War, and the War of 1812.
They understood quite well that their citizenship was whatever the sovereign of the state in which they were present said their citizenship was to be. If the sovereign commanded that the child owed allegiance at birth to that sovereign and not the father's sovereign, then the child was born with allegiance to that sovereign and natural born citizenship in that soveriegn's domains. If the sovereign commanded that the child owed allegiance to the father's sovereign and not the sovereign, then the child was born with allegiance to he father's sovereign and natural born citizenship in the domains of the father's sovereign. Citizenship and natural born citizenship is whatever the sovereign commanded the child's allegiance to be.
Whenever and wherever two sovereigns dispute the allegiance owed by a child, there exists a conflict which may cause undesirable consequences for that child. It was true in the 18th Century, and it is still true in the 21st Century.
Vattel reported what was obvious and apparent to everyone. A natural born citizen is born with the allegiance of the parents and therefore the citizenship of the parents, otherwise the parents' society would cease to exist. In this way Vattel was implying the English or British practice of commanding the allegiance of the children of foreign citizens constituted the conquest and extinguishment of a society and its culture. Vattel likely had this problem in mind at the time he wrote the passage. He was likely thinking about the fate of the non-English communities in British North America and elsewhere around the world following the Treaty of Paris 1763.
Likewise, the Constitutional Convention and the Founding Fathers were conscious of the threat presented by the English-British policy of commanding the allegiance of the children of parents foreign to the English kingdom and British Empire. The natural born citizen clause in the Constitution represented just one modest part of an effort to restrain the influence and control of foreign born pretenders to the domination of political affairs in the new Republic of the United States of America. The English-British policy of commanding the allegiance of every person born in the British domains presented a threat to every non-English-British community by coopting their children's loyalties.