“Natural born citizen” simply means that someone who falls within the specified criteria is a citizen at birth (meaning that person doe not have to go through a naturalization process).
Under U.S. law, a person is a natural born citizen if he or she is born of a parent who was a U.S. citizen at the time of that birth, no matter where the physical birth occurred.
Someone on this thread — and I don’t know of it was you or not, but that is irrelevant — said that to be a natural born citizen BOTH parents had to be U.S. citizens at the birth of that person. That is just wrong. I am a natural born citizen (meaning I was automatically a U.S. citizen at my birth) even though my mother was not a U.S. citizen, and had not lived in the U.S. for five years when I was born. But, my father was a U.S. citizen, as were his parents, and his grandparents (even though two of his grandfathers fought for the Confederacy).