If "natural born citizen" is a synonym for "citizen," then there is no reason for adding the exception "or a Citizen of the United States, at the time of the Adoption of this Constitution." None at all. Being a citizen is not sufficient, unless you happened to be alive when the Constitution was adopted.
So what, then, is a "natural born citizen"? To answer that question definitively will require a full examination of the concepts and history of citizenship.
Types Of Citizenship: Jus Soli, Jus Sanguinis, Natural Born, Native Born, Naturalized
Jus soli citizenship: "Jus soli" is a Latin phrase meaning "law of the soil." Jus soli citizenship is any citizenship that inheres in a person based on the location of his or her birth.
Jus sanguinis citizenship: "Jus sanguinis" is a Latin phrase meaning "law of the blood." Jus sanguinis citizenship is any citizenship that inheres in a person based on his or her ancestry.
Native born citizenship: A native born citizen is one whose citizenship derives from the facts of his birth, and who becomes a citizen at the moment of birth. In both US and British law, those born within the sovereign territory of the country or born to parents who are citizens (subjects) of the country when the person is born are native citizens (subjects.) Native born persons are said to have "birthright citizenship." Note that one can be "native born" either by the "jus soli" principle or by the "jus sanguinis" principle.
Naturalized citizenship: A naturalized citizen is one whose citizenship is granted by statute or by the decision or act of a sovereign.
Natural born citizenship: A natural born citizen is one whose citizenship is beyond dispute, not synthetic, not subject to conflicting claims, not granted by statute or by any act of a sovereign, but inheres naturally in the person according to principles that don't depend on laws or decisions of a sovereign. [The rest of this essay will fully justify this definition]
The 14th Amendment created an implicit distinction among 14th Amendment native-born citizens, and statutory native-born citizens. A 14th Amendment native-born citizen is any person who (a) was born in the United States, and (b) was subject to U.S. jurisdiction at the time of his or her birth. In contrast, a statutory native-born citizen is a person who does not qualify for birthright citizenship under the 14th Amendment, but receives U.S. citizenship, at birth, by laws enacted by Congress. For example, foreign-born children of American parents do not receive citizenship from the 14th Amendment; such children acquire U.S. citizenship, at birth, by statute.
So those born outside the United States to parents who are US citizens at the time of the person's birth are both native citizens and also naturalized citizens, since their citizenship is a) granted to them by an Act of Congress (based on Congress' Constitutional authority "To establish an uniform Rule of Naturalization,") and b) effective from the instant of their birth, based on the fact that the person's parents were US citizens at that moment.
Similarly, it is necessary to distinguish between Constitutional and statutory natural born citizens:
These distinctions are not my invention. The U.S. Department of State Foreign Affairs Manual—7 FAM 1130 (page 9) says:
...the fact that someone is a natural born citizen pursuant to a statute does not necessarily imply that he or she is such a citizen for Constitutional purposes
If we were to define "natural born citizen" to mean anyone who is a "citizen at birth", our definition of "natural born citizen" would be statutory because it would depend on the statute or law which defines "citizen at birth". Under existing law, all children born in the United States (except the children of foreign diplomats) are "citizens at birth". Therefore, under existing law, almost all children born in the U.S.—including children of illegal immigrants—could be regarded as statutory natural born citizens.
H.R.1940, also known as the Birthright Citizenship Act of 2007, would change the existing law so that it would no longer grant "citizenship at birth" to children of illegal immigrants. If Congress were to pass H.R.1940, it would alter the meaning of "citizen at birth", and therefore would alter our statutory definition of natural born citizen. If H.R.1940 were enacted, the U.S.-born children of illegal immigrants could no longer be regarded as statutory natural born citizens.
Is "Natural Born Citizen" Equivalent To "Natural Born Subject" As Defined By English Common Law?
The argument is made that "natural born citizen" means the same thing that "natural born subject" means in English common law, except for the differences in meaning between a subject and a citizen. That idea is false. The full proof of that assertion is presented below, in the section entitled "The Semantics Of Natural Born Subject In English Common Law." The short version (executive summary) is as follows:
The English common law did not distinguish between a "natural born subject" and a naturalized subject. Under English common law, once a person became naturalized, he or she was deemed to be a "natural born subject." Hence, under English common law a naturalized citizen was considered a "natural born subject."
Therefore, giving the "natural born Citizen" clause the same meaning as a "natural born subject" would have allowed a naturalized citizen to be eligible to be President of the United States. But Article II, Section 1, Clause 5 mandates that only a "natural born Citizen" is eligible to be President. The clause is written as "No person except . . . shall be eligible . . ." which means that one must be a "natural born Citizen" in order to be eligible to be President, with no exceptions other than for those who were citizens when the Constitution was adopted.
The way we in the US have interpreted the "natural born Citizen" clause since the beginning of the Republic, a naturalized citizen is not eligible to be President. But assuming the "natural born Citizen" clause had the same meaning as a "natural born subject," with the Constitution as written it would not have conveyed in any manner that a naturalized citizen was not eligible to be President. No where do we find in the Constitution any statement that a naturalized citizen is not eligible to be President. To reach this conclusion, we have always relied upon the "natural born Citizen" clause itself which we have compared with the fact that the Framers prescribed in Article I that naturalized citizens were eligible to be Senators ("nine Years a Citizen of the United States") and Representatives (seven Years a Citizen of the United States") . The manner in which the Framers provided that Senators and Representatives needed to be "Citizen of the United States" for only a certain amount of years shows that the naturalized citizen class was included within "Citizens of the United States" and not within "natural born Citizens." This shows that naturalized citizens were not part of "natural born Citizens."
So equating the meaning of a "natural born Citizen" to a "natural born subject" would have allowed naturalized persons to be President, a result that we have rejected from the beginning of the Constitutional Republic. Such a meaning would have created an exception to the "natural born Citizen" clause which would have eviscerated the clause itself. Additionally, since Congress has the power under Article I, Section 8, Clause 4 to make uniform the naturalization laws, such a meaning would have given Congress the power to decide who could be President by simply changing the naturalization requirements. The Framers, fearing that Congress would allow foreign influence to creep into the office of President if it were given the power to select the President, did not give Congress such power.
But the argument is also made that "natural born citizen" differs from "natural born subject" in two ways, not just one: 1) The difference in meaning between a subject and a citizen, and 2) "natural born citizen," unlike "natural born subject," excludes naturalized citizens. But this thesis also is easily falsified:
Firstly, as soon as a second difference is posited, the entire rationale for the argument collapses utterly. That rationale is based on the premise that US citizenship law derives directly from English common law regarding who is or is not a British subject. But if "natural born citizen" differs in meaning from "natural born subject" in any way other than is required by the fact that the US has citizens and Britain has subjects, that invalidates the only premise and justification for defining the US term based on the definition of the British term. It breaks the symmetry, and sets the precedent that the meaning can differ in other ways as well. In other words, if the meaning of the two terms differ in at least one respect other than the difference between subject and citizen, what prevents them from being different in yet a third way? Or a fourth? And so on, ad infinitum.
Secondly, the historical facts are clear and undeniable, and are strongly supported by Supreme Court rulings: English common law was the basis for the common law of the original British colonies, and then of the original States of the Union, but was not the basis for the common law of the United States Federal government.
The framers rejected the notion that the United States was under English Common Law, “The common law of England is not the common law of these States.” —George Mason one of Virginia’s delegates to the Constitutional Convention.
One reason such is the case is because the US was founded as a Constitutional Republic, not as a monarchy. The founding principles were different, and in fact were an explicit rejection of key foundational principles of English law and English government. Another issue was simply that each colony was founded at a different time, adopted English common law as its own at the moment of its founding, but then evolved its own common law going forward, independently of Great Britain and the other colonies. So there was no common "common law" among the founding States!
Finally, words and terms of art have the meanings they do because of their utility in the culture and society that uses them. New words and phrases are created with particular meanings, and existing words and phrases are given new meanings, because those new meaning serve the purposes of those who use them, and old meanings no longer do. So that raises the question of the purpose or intent of the purely American term "natural born citizen," especially in the context of the new Constitutional Republic being created by those at the Constitutional Convention.
Original Intent
In Alexander Hamilton's first draft of the U.S. Constitution, a person had to be "born a citizen" of the United States in order to be eligible to serve as president. However, in July 1787, John Jay wrote a letter to George Washington, recommending that the presidential eligibility requirement be changed from "born a citizen" to "natural born citizen". The stated purpose of the change was to exclude "foreigners" from the presidency:
“Permit me to hint whether it would not be wise and seasonable to provide a strong check to the admission of foreigners into the administration of our national government; and to declare expressly that the command in chief of the American army shall not be given to, nor devolve on any but a natural born citizen.”
From this information alone, we may infer that:
The wording change from "born a citizen" to "natural born citizen" doesn't make any sense—it would not have excluded anyone not already excluded by the "born a citizen" requirement—unless the term "natural born" is understood as more restrictive than "native born." To fully eliminate the possibility of someone who could possibly be classified as a foreigner becoming President, the meaning of "natural born citizen" would have to include only persons who, from birth, owed allegiance to the United States exclusively and did not acquire, since birth, any foreign allegiance or nationality.
The change from "born a citizen" to "natural born citizen" would not have provided any additional protection against foreign influence in the presidency—that is, Jay's wording change could not have barred from the presidency anyone who was not already barred by the "born a citizen" requirement—unless the term "natural born citizen" meant a person who was not a "foreigner" (a citizen or a subject of any foreign country) since birth.
John Jay's letter to Washington establishes the fact that the Framers were worried about the undivided loyalty of the President, and thought that the requirement that he be a "natural born citizen" would be sufficient to prevent anyone with foreign allegiance (anyone who could be claimed as a subject or citizen of a foreign sovereign) from serving as President. But how could that be, if "natural born citizen" differs from "natural born subject" solely in the difference between a subject and a citizen? A British "natural born subject" could have multiple nationalities, and owe allegiance to multiple sovereigns. And many nations claim anyone with at least one parent (sometimes it must be the father, sometimes it must be the mother, sometimes both) who is a citizen or subject of that nation as a citizen/subject also.
In view of all the above facts and reasoning, it is beyond any possibility of dispute that the only way the "natural born citizen" requirement can prevent a person from having allegiance to a foreign sovereign is if its meaning is the same as the one de Vattel defined and labelled "les naturel, ou indigenes," and which a professional translator translated into English as "natural born citizen" just a few short years after the "natural born citizen" requirement was written and ratified in the new US Constitution. Literally and normatively, the words "les naturel, ou indigenes" mean "the natural ones, the natives." So why did the translator render them into English as "natural born citizen," unless it was his expert opinion that the meaning of "natural born citizen" in the Constitution matched the meaning of the concept defined by de Vattel, where de Vattel specifies the purest form of citizenship as requiring both jus soli ("law of the soil") citizenship and jus sanguinis ("law of the blood") citizenship—with BOTH parents being citizens?
Clearly, if both your parents are citizens (or subjects) of the same sovereign, and you were born in that same sovereign's territory, then and only then is it impossible for any foreign sovereign to have a claim to your allegiance under the law of nations as commonly understood. John Jay's request to Washington makes no sense otherwise. If that reasoning is sound, then "natural born citizen" must have been intended to have the same meaning as de Vattel defined for his term-of-art phrases "les naturels, ou les indigenes."
Consider again Article II, section 1, pa. 5: "No Person except a natural born Citizen, or a Citizen of the United States, at the time of the Adoption of this Constitution, shall be eligible to the Office of President; neither shall any Person be eligible to that Office who shall not have attained to the Age of thirty five Years, and been fourteen Years a Resident within the United States." That limits who may be President to persons who meet the following requirements:
Why did the Constitutional Convention include that last exception, allowing those who were citizens at the time the Constitution was adopted to be President?
Before answering that question, consider the case of Congressman Smith. He was born in South Carolina before the American Revolution. At the time of the Revolution, he was not yet an adult. His parents were British loyalists, and fought against the Revolution. But after the Revolution and the adoption of the Constitution in 1787, he was elected to Congress. But his right to be seated was challenged on the basis that he was not a citizen, due to the actions of his parents.
James Madison himself spoke in defense of the fact that Mr. Smith was a citizen. The reasoning he used is decisive with respect to understanding the reason for the exception in the Constitution to the "natural born citizen" requirement.
Madison essentially argued that Mr. Smith was a citizen because of where he was born, and because he was a minor when his parents sided with the British loyalists against the American Revolutionaries. He focused on that point, because he obviously felt that any adult who sided with the British loyalists would not qualify as citizens, regardless of where they were born (he explains the reason for that.) Bear in mind that the Constitution allows naturalized citizens to serve in Congress, there is no requirement that one have "birthright citizenship" (whose normative definition means either "jus soli" OR "jus sanguinis" citzenship (OR, not AND.)) But Madison nevertheless argued that Mr. Smith was a citizen from birth, by reason of his place of birth alone, and explicitly not due to his parentage, because (as Madison argues) his parents never were US citizens at all.
Madison's argument prevailed, and Mr. Smith was seated as a Congressman. The Congress accepted Madison's argument that Mr. Smith had birthright citizenship solely due to the location of his birth in South Carolina—when South Carolina was a British Colony, and not yet a State of the United States. By that same logic, most residents of the US at the time the Constitution was adopted were native citizens of the US by their place of birth alone.
So, based on Madison's argument (which Congress accepted,) if "natural born citizen" means simply "native born," or means essentially the same as "natural born subject" (differing only to the extent that a citizen differs from a subject, and also excluding those whose citizenship was acquired by naturalization) then any citizen of the US at the time the Constitution was adopted would satisfy the "natural born citizen" requirement, so there would be no need for the exception, and its inclusion in the Constitution makes no sense. No sense at all.
But if "natural born citizen" means "born on US soil, with parents who were US citizens when their child was born," then it would in fact be true that no one alive at the time could have satisfied the "natural born citizen" requirement, in which case there is a good reason for the exception.
So the evidence is clear, compelling and irrefutable: The reason the Constitutional Convention required that the President (and later, by Amendment, the Vice President) be a "natural born citizen" is that they were concerned that the person who would be head of State, chief executive and Commander-In-Chief of the US armed forces have absolutely no conflicts of interest, legal obligations or loyalties to any foreign sovereigns or foreign powers.
Some nations claim you as their citizen or subject based on where your were born, some based on who you your parents were (father and/or mother,) and some based on both together. By requiring that the President be born at a location where the US is sovereign, any foreign claim on the President to allegiance based on his place of birth is precluded. By requiring that the President be born to parents who are solely US citizens, any foreign claim on the President to allegiance based on his parentage is precluded.
You may disagree with the goal of the Constitutional Convention, and/or with the means they chose to achieve it. But it's not a technicality, not an anachronism no longer relevant in modern times, nor is it racist. Especially in modern times, it enables persons of any race or ethnic heritage to become President. And it's what the Constitution requires. And if one faction gets to disregard the Constitution because they disagree, then that sets a precedent where all other factions can do the same. And get away with it. Is that really what you want? _________________________________
The Semantics Of Natural Born Subject In English Common Law
During the 17th and 18th centuries, the term "natural born" had a general meaning and a specific meaning (see below for substantiation.) In the general sense, all English subjects (except denizens) -- including foreign-born and naturalized subjects -- were called "natural-born," regardless of how or when they acquired their English subjecthood. Nearly all children born on English soil, including children of alien parents, were natural-born in the general sense. However, in the specific sense, "natural born" referred only to persons who were born within the sovereign's territory, of parents who were under the sovereign's actual obedience or allegiance (see below for substantiation). Such persons, at birth, owed natural allegiance to the English king exclusively, and did not (at birth) owe allegiance to any other sovereign.
The modern-day mainstream consensus is that "natural born" should be understood according to its general sense, which means that anyone born on U.S. soil is a natural born citizen. However, multiple historical sources (and the arguments and evidence I have already made and presented above) comprehensively and irrefutably indicate that, when the Constitution was written, "natural born," as used in "natural born citizen," was understood according to its specific sense, not its general sense.
What was an 18th-century English "subject"?
During the 18th century, the population of England and its colonies was divided into three categories: foreigners, aliens, and subjects. The difference among them was their allegiance. Subjects owed permanent allegiance to the English king; aliens owed temporary (local) allegiance; and foreigners did not owe any allegiance.
Allegiance—sometimes called ligeance and, at other times, also called obedience—was faith, loyalty and service that someone owed to the king, in return for the king's governance and protection.
Subjects and aliens were collectively referred to as the people of England. The people did not include foreigners.
Prior to the American Revolution, the words subject and citizen had separate and distinct meanings. The two were not synonymous. In 18th-century England and its colonies, some—but not all—English subjects were also English citizens.
Every English subject was either a denizen or a natural-born subject.
Subjects had property rights; alien and foreigners did not. Subjects could acquire and hold real (non-movable) property such as land, and bequeath it to their heirs. Aliens and foreigners were not permitted to possess English real estate, other than a house or apartment for their own personal habitation.
Foreigners: Foreigners were foreign citizens or subjects who had no intention of making England their "home". They were living in England, but had no intention of becoming a part of English society. Foreigners included members of foreign-controlled religious orders, ambassadors from foreign countries, members of foreign royalty, and foreign merchants visiting English territory solely for trade or business. (Berry). Foreigners did not owe allegiance to the English king, and were not under his protection. Nevertheless, the king provided safe conduct for most foreigners.
Aliens: An alien was a foreign citizen or subject who had established residence, or domicile, on English soil (Berry). While living within the king's realm, alien friends owed temporary ("local") allegiance to the king and were under the king's protection. When an alien friend departed from English territory, her or his allegiance to the king automatically terminated. Alien enemies were citizens or subjects of a foreign country that was hostile towards England. They, like foreigners, did not owe any allegiance to the king and were not under the king's protection.
Denizens: During the early 1600s, the word "denizen" had a broad and general meaning. It referred to anyone who became an English subject by artificial means, such as a public or private act of Parliament, letters patent issued by the king, or military conquest:
[The] denization of an alien may be effected three manner of wayes: by Parliament, as it was in 3 Hen. 6. 55. in Dower; by letters patents, as the usual manner is; and by conquest, as if the King and his subjects should conquer another Kingdome or dominion ... (Coke(1608), p.178)
By the time the U.S. Constitution was written in 1787, the word "denizen" had acquired a more narrow and specific meaning. It referred only to persons who became English subjects by acts of the king (letters patent or military conquest). Persons who became subjects by parliamentary statute or naturalization were no longer called "denizens"; instead, they were called "natural born subjects."
Natural-Born Subjects: A natural-born subject was anyone who acquired subjecthood either by birth or by act of Parliament. When the U.S. Constitution was being written, all English subjects—except persons who were made denizens by the king—were called natural-born subjects. Actual natural-born subjects were subjects by "nature and birthright". They were born on English soil, to parents who were under the king's "actual obedience". All other natural-born subjects were naturalized; they acquired English subjecthood by a public or private act of Parliament; they were deemed to be natural-born subjects by law but were not natural-born subjects in fact.
This is authoritatively established by Francis Bacon (Case of the Post-Nati of Scotland, 1608. Also, James Spedding, Works of Francis Bacon, Volume XV.) In Bacon's view, there were four categories or "degrees" of persons: 1) alien enemies, 2) alien friends, 3) denizens, and 4) natural-born subjects. Persons became natural-born subjects either by birth or by acts of Parliament, but not by denization (first 3 definitions omitted as not relevant):
The fourth and last degree is a natural born subject, which is evermore by birth, or by act of parliament; and he is complete and entire.<p>So, just as we in the US have found it necessary to distinguish between Constitutional "natural born citizens" and statutory "natural born citizens", the Brithish found it necessary to distinguish between by birth or actual "natural born subjects" and statutory (by act of Parliament) "natural born subjects."
Ways of becoming a subject: A person became an English subject either naturally (by natural law) or artificially (by human action or man-made law). Persons who were subjects by natural law were called subjects born. Persons who received subjectood artificially (from Parliament or the king) were called subjects made.
Every subject is either natus, born, or datus, given or made (Coke (1608), p.206)
Except in special cases, a child was a subject born (a subject by natural law) if it met two requirements at the time of its birth: a birthplace requirement (the child had to be born within the king's realm), and a parental obedience requirement (the child's parents had to be under the "actual obedience" of the king):
There be regularly (unless it be in special cases) three incidents to a subject born. 1. That the parents be under the actual obedience of the King. 2. That the place of his birth be within the King's dominion. And, 3. The time of his birth is chiefly to be considered; for he cannot be a subject born of one kingdom that was born under the ligeance of a King of another kingdom, albeit afterwards one kingdom descend to the King of the other. (Coke (1608), p.208)
Statute: Parliament may enact laws which automatically naturalize certain children at birth. Such laws were sometimes called public acts of Parliament. By the time William Blackstone (1723-1780) wrote his Commentaries (1765-1769), Parliament had enacted laws which conferred subjecthood, at birth, to foreign-born children of English fathers:
...all children, born out of the king's ligeance [territory], whose fathers were natural-born subjects, are now natural-born subjects themselves, to all intents and purposes, without any exception; unless their said fathers were attainted, or banished beyond sea, for high treason; or were then in the service of a prince at enmity with Great Britain. (Blackstone)
A law, enacted in 1604, declared English-born children of alien parents to be "denizens" (in the general sense):
To place the Children, born within this Realm, of foreign Parents, in Degree for the first Birth or Descent only, as Aliens made Denizens, and not otherwise. (House of Commons Journal, Volume 1, 21 April 1604)
Foreign-born children of English fathers, and English-born children of alien parents, were naturalized at birth, by English law:
Furthermore as the law of England must favor naturalization as a branch of the law of nature, so it appears manifestly, that it doth favour it accordingly. For it is not much to make a subject naturalized by the law of England: it should suffice, either place or parents. If he be born in England it is no matter though his parents be Spaniards, or what you will: on the other side, if he be born of English parents it skilleth not though he be born in Spain, or in any other place of the world. In such sort doth the law of England open her lap to receive in people to be naturalized; which indeed sheweth the wisdom and excellent composition of our law ... (Bacon, Francis, pp.664-665)
Naturalization: An alien adult could become an English subject through a legal process called "naturalization," also called a private act of Parliament. Person who were naturalized in this manner acquired the same rights as subjects born, but could not hold public office. Subjecthood by naturalization was available only to Christians who took the Oath of Supremacy and Oath of Allegiance (see English Oaths, 1642). Naturalization had a retroactive effect. When someone became a naturalized subject, all of his children received property and inheritance rights, even if they were born prior to the act of naturalization:
Naturalization cannot be performed but by act of parliament: for by this an alien is put in exactly the same state as if he had been born in the king's ligeance; except only that he is incapable, as well as a denizen, of being a member of the privy council, or parliament, &c. No bill for naturalization can be received in either house of parliament, without such disabling clause in it. Neither can any person be naturalized or restored in blood, unless he hath received the sacrament of the Lord's supper within one month before the bringing in of the bill; and unless he also takes the oaths of allegiance and supremacy in the presence of the parliament. (Blackstone)
Aliens could earn naturalization by (a) serving two years on an English warship during time of war, (b) serving three years on an English whaling vessel, (c) residing seven years on an English-run plantation, or (b) serving two years in America (Cunningham, Law Dictionary, Volume 2, 1771, section titled "naturalization").
Denization by the King: The king had the authority to issue letters patent to aliens, thereby transforming them into denizens (in the specific sense). The rights of denizens were limited by the terms and conditions of the letters patent, which varied from person to person. Denization was not retroactive. It did not confer any rights to children which were born prior to their fathers' denization:
A denizen is an alien born, but who has obtained ex donatione regis letters patent to make him an English subject: a high and incommunicable branch of the royal prerogative. A denizen is in a kind of middle state between an alien, and natural-born subject, and partakes of both of them. He may take lands by purchase or devise, which an alien may not; but cannot take by inheritance: for his parent, through whom he must claim, being an alien had no inheritable blood, and therefore could convey none to the son. And, upon a like defect of hereditary blood, the issue [children] of a denizen, born before denization, cannot inherit to him; but his issue [children] born after, may. A denizen is not excused from paying the alien's duty, and some other mercantile burdens. And no denizen can be of the privy council, or either house of parliament, or have any office of trust, civil or military, or be capable of any grant from the crown. (Blackstone)
Summary: The population of England and its colonies was divided into three categories: foreigners, aliens and subjects. Subjects owed permanent allegiance to the king; aliens owed temporary (local) allegiance to the king; and foreigners did not owe any allegiance to the king.
There were two kinds of English subjects: subjects born and subjects made.
Subjects born were subjects "by nature and birthright". They were actual natural-born subjects. They were born on English soil, to parents who were under the "actual obedience" of the king.
Subjects made acquired subjecthood either from Parliament or from the king. Those who acquired subjecthood from the king were called denizens. Those who acquired subjecthood from public or private acts of Parliament were naturalized (as opposed to actual) natural-born subjects.
A public act of Parliament was a statute which granted subjecthood automatically to anyone who met certain criteria. Public acts included laws which conferred subjecthood, at birth, to foreign-born children of English fathers and to English-born children of alien parents.
A private act of Parliament, also called "naturalization," was a legal process which conferred subjecthood to a specific individual or group.
All English subjects, except persons made denizens by the king, were called "natural-born subjects". However, only subjects born were actual natural-born subjects. All other natural-born subjects were naturalized; they were deemed natural-born by law but were not so in fact.
All English subjects had property rights. They could acquire and possess English real estate and bequeath it to their heirs. Aliens and foreigners could own movable property, but could not hold unmovable property except a house or apartment for their own personal habitation.
Conclusion
From the above, it should be emphatically evident that the term of art in British law "natural born subject" has a very complex set of meanings that are very specific to the needs and realities of British culture and society. It's ostensive meaning in specific usages was dependent on context.
If "natural born citzen" is totally analogous to "natural born subject" other than for the difference between a subject and a citizen, then its meaning includes both subject born and subject made. In which case, the Constitutional grant of power to Congress to define uniform rules of naturalization would give them the power to make even naturalized citizens eligible to be President, in contradiction to the universal understanding of Article II, section 1, pa. 5 from the 1787 up to the present. Exactly as I argued above. So that cannot be the intended meaning.
However, if "natural born citizen" means a subject born, then that meaning matches exactly with the definition of "les naturels, ou indigenes" as defined by de Vattel.
This thread deserves a bookmark for this reply.