The law of acquisition of citizenship grants children born outside the United States to one or more U.S. citizens the ability to claim American citizenship. Though this law has always automatically granted citizenship to children born abroad if both parents were U.S. citizens at the time of birth, it has been modified several times over the years concerning children born abroad to only one U.S citizen at the time of birth. For example, a considerable number of children with only one U.S. citizen parent have lost or never acquired American citizenship status because they failed to meet residency requirements imposed by previous laws. At one time, children born abroad before May 23, 1924 couldn’t acquire U.S. citizenship if their father wasn’t an American citizen, regardless if their mother was a citizen at the time of birth. Such requirements have been revoked through recent amendments, most notably under The Immigration and Nationality Technical Corrections Act passed in 1994. As it stands now, the law of acquisition of U.S. citizenship grants citizenship to children born abroad to one citizen parent as long as the citizen parent meets residency requirements designated by law at the time of birth. Children born abroad out-of-wedlock to a citizen father or citizen mother can also claim their citizenship provided the citizen parent meets the required legal and residency requirements at the time of birth. Since changes in the laws governing acquisition of citizenship were seldom retroactive, you must apply the law that was passed immediately prior to your date of birth. If you’re eligible to apply for citizenship, you need to file Form N-600 (N-six hundred), or Application for Certificate of Citizenship, at the appropriate Immigration and Naturalization Service office. You must include the appropriate fee and necessary evidence to establish your claim to citizenship, such as birth, adoption, and marriage certificates. You’ll be interviewed and if your application is approved, you’ll be required to take the Oath of Allegiance when receiving your certificate of citizenship. Individuals residing outside of the U.S. may apply at a U.S. consulate or embassy and must provide similar documentation.