The naturalization act of 1790 says that a person born to a citizen parent beyond the shores of America shall be as natural born, meaning the same. It is what set the precedence that being born inside the boundaries of the US is NOT a requirement of NBC.
Regardless, you failed to mention that The Naturalization Act of 1790 was repealed by the Naturalization Act of 1795 with the lead of then rep. James Madison and the approval of George Washington and specifically changed "shall be considered as natural born citizens" to "shall be considered as citizens of the United States."
Article II, Section 1, Clause 5 provides that a Citizen of the United States was eligible to be President only if born before the adoption of the Constitution and that thereafter only a natural born Citizen was so eligible. Hence, Congress referring to one as a citizen rather than a natural born citizen, given the presidential eligibility requirements of Article II, was a serious thing.
By changing the language from "natural born"" to citizen", they DID set the definition for those who are born to citizens (two citizen parents) outside the jurisdiction or limits of the United States. From 1790 to 1795 this condition gave us the status of "natural born". After 1795, this gave us the status of "citizen".