Here is the dilemma that I find in a statement like this.
Today, "birthright" is interpreted to mean citizenship at birth (born here).
I would suggest that in the 1790s, travel in and out of the United States was impossible for most citizens. Only the most wealthy (or ambassadors of the United States) could afford passage on sailing ships to England or France for a six-week voyage under hardship conditions. If someone did manage to obtain such passage, they would stay in Europe for years before returning to the United States.
Regarding jus soli or jus sanguinis, people's lineage to the land was well-known. I would think that to be true of most people in the 1790s; the townspeople of any town in the post-colonial United States would have known who begat whom through the generations (they used to document that in family Bibles), and so "land" was a proxy for citizenship by parentage, too.
That means they knew who the newcomers were, too. Many people could trace their ancestry back to the first settlers of the colonies. Given that people didn't travel far distances back then, "land" and "parentage/ancestry" were synonymous in practice.
It's my belief that "born here" as the sole determinant in "natural born citizen" in 1789 had a completely different interpretation than "born here" does in 2024.
-PJ
You introduce an interesting nuance of the definition of NBC. The citizenship of the initial several presidents, of course, is not relevant - they became citizens the minute the gavel finally dropped in the 1787 Constitutional Convention. On the other hand, what is relevant is the citizenship of their parents
Arguably the initial presidents could have been NBC's had they been born to parents who were citizens of the ratifying states prior to 1787 - but clearly the founders did not agree with that view and thought they had to provide two separate options with the latter applicable to only those candidates alive at the adoption. If a candidate was not alive on the first day of the nation, the NBC requirement applied.