Unless that law was written in 1787 before the Constitution was ratified, it doesn't matter what it says. You can't change the meaning of constitutional terms by passing a law.
If you could, then they could redefine "arms" to mean sling shots, and there goes the second amendment.
It is the Constitution in Article 1 Section 8 that specifically enumerates the power that Congress has with regarding making the rules of naturalization. That means Congress has the authority to say who needs naturalization, and who does not (naturally born as a citizen). Just as the very first Congress (and was signed by President George Washington) established the first rules of naturalization, Title 8 section 1401 is the current law as it reflects the will of Congress under that enumerated power.