“A person born out of the jurisdiction of the United States can only become a citizen by being naturalized, either by treaty, as in the case of the annexation of foreign territory, or by authority of congress, exercised either by declaring certain classes of persons to be citizens, as in the enactments conferring citizenship upon foreign-born children of citizens, or by enabling foreigners individually to become citizens by proceedings in the judicial tribunals, as in the ordinary provisions of the naturalization acts.” U.S. v. Wong Kim Ark, 169 U.S. 649, 702-703
By action of Congress. One thing is certain, the Constitution is not a legal code but an instrument of government. It does not come with a glossary, nor did the Secretary gives anything like a stenographic records of the meeting. Even Madison’s notes are incomplete because he could not be everywhere. In short, the meaning of “natural-born citizenâ€except in the most clear cases, is moot. Someone born to American parents in the country is undoubtedly eligible. Someone born to alien parents in their country, is not. But the term is not absolute. We are dealing with a difference in degree, not kind.