UNITED STATES CITIZENSHIP
Under the laws of the United States, which have changed considerably over time, there are three pathways to U.S. citizenship, namely:
1. By application for naturalization.
2. By acquisition at the time of birth — either through birth in the territorial United States, or by birth abroad to U.S. citizen parents.
3. By derivation, through the naturalization of parent(s) with whom you lived as a minor in the United States.
While every permanent resident who seeks to become a naturalized citizen must be questioned carefully to determine whether he or she may be a U.S. citizen already, most potential N-400 applicants know if there is some possibility that they are citizens already.