The courts have never resolved this. Tribe and Olson's opinion performed at the request of the Senate on McCain's eligibility found that you could be a natural born citizen thru jus solis OR jus sanguinis. In fact, they mentioned Obama's eligibility in that opinion and judged him natural born by virtue of being born in Hawaii.
if being born on the soil is the only qualification for a term in common use world wide at the time of the signing... then what’s the difference between a person born in the country of 2 foriegn parents and a natural born citizen?
the fact is, the term means someone is a citizen naturally ... as there are no alternatives.
it’s that simple
and a supreme court case did reference the definition of natural born citizen in minor v happersett (1874)