According to the INA , a U.S. citizen is a native-born, foreign-born, or naturalized person who owes allegiance
to the U.S. and who is entitled to its protection. In addition to the naturalization
process, the U.S. recognizes the U.S. citizenship of individuals according to two
fundamental principles: jus soli, or right of birthplace, and jus sanguinis, or right
of blood (deriving citizenship through parent’s citizenship).
IMPORTANT: Not all people born in the U.S. are U.S. citizens, see RM 10210.500B.1 above and RM 10211.001B.3.
Individuals can become U.S. citizens by various means, including
Naturalization - The process by which individuals become citizens after birth.
Collective naturalization - The process by which individuals become citizens by an
Act of Congress or Presidential Proclamation without individual petition.
Derivative citizenship - The process by which individuals become citizens if they
are born abroad to a U.S. citizen and meet certain, other, requirements. For more
information on derivative citizenship, see GN 00303.300I.