Say what?
Where did his mother live?
Doesn’t matter where his mother lived before his birth.
What matters is where she lived after his birth on her 18th birthday.
“Pursuant to American citizenship laws, you are a U.S. citizen if ALL of the following are true:
* (a) One of your parents was a U.S. citizen when you were born;
* (b) Your citizen parent lived at least 5 years in the United States before you were born; and
* (c) At least 2 of these 5 years in the United States were after your citizen parent’s 14th birthday.”