John Adams said, clearly, that Congress needed to do more to define Citizenship, and that statement was even AFTER Ratification.
You are wrong.
Our Founders only wanted to insure that any future President was a Citizen at the Moment of Birth.
Since Congress has said that you can be a Citizen at Birth if born on foreign soil, if born by a Citizen Parent(s) of certain age, and changed said requirement a few times, there are many Natural Born Citizens who were born on foreign soil.
CONGRESS has the power to decide Citizenship, PERIOD! All forms of Citizenship.
Congress could not declare that a citizen of a foreign country, at birth, was a “Natural Born Citizen” of the United States, retroactively, by statute. Congress is restrained by the Constitution from doing that.
However, Congress is free to determine the rules for “Natural Born Citizen” -— the rules for how to obtain BIRTHRIGHT CITIZENSHIP are within the powers of Congress. Birthright Citizenship is all “Natural Born Citizen” implies.
-PJ