During the debates on ratifing the Constitution in New York several amendments were suggested.
On Saturday July 5th, 1788, Mr. Gilbert Livingston and Mr. Melancton Smith suggested the following amendment:
"Resolved, as the opinion of this committee, that the Congress should appoint, in such manner as they may think proper, a council to advise the President in the appointment of officers; that the said council should continue in office for four years; that they should keep a record of their proceedings, and sign the same, and always be responsible for their advice, and impeachable for malconduct in office; that the counsellors should have a reasonable allowance for their services, fixed by a standing law; and that no man should be elected a counsellor who shall not have attained to the age of thirty-five years, and who is not either a natural-born citizen, or has not become a citizen before the 4th day of July, 1776."
http://www.constitution.org/rc/rat_ny.htm
And in the final ratification document sent to Congress, the New York Convention asked them to consider adding the following amendment,
"That no Persons except natural born Citizens, or such as were Citizens on or before the fourth day of July one thousand seven hundred and seventy six, or such as held Commissions under the United States during the War, and have at any time since the fourth day of July one thousand seven hundred and seventy six become Citizens of one or other of the United States, and who shall be Freeholders, shall be eligible to the Places of President, Vice President, or Members of either House of the Congress of the United States."
http://avalon.law.yale.edu/18th_century/ratny.asp
The New York ratifing convention included both John Jay and Alexander Hamiliton.
So who do you think they would have considered to be a citizens before July 4th, 1776?
In all cited examples they differentiate between natural born citizens and those who were citizens at the time of the adoption of the Constitution - that being the 4th of July 1776. That is my point - that they are two distinct and separate categories of “citizen” - it was not the case that those who were citizens at the time of the adoption of the Constitution were a subset of “natural born citizens”.
The language of the Constitution says those who were citizens at the time of the adoption of the Constitution - not that they were MADE citizens at the very moment that the Constitution was adopted.
Anyone who was a citizen by birth or naturalization according to the laws of the 13 colonies would be an American citizen before that. But it would be hard to be a citizen of the United States before they were United and before they were States.
They became US citizens under the category “citizen at the time of the adoption of the Constitution”.