Thanks to Katherine Anne Brady for this section.      Some people who were born outside the United States inherited U.S. citizenship from their U.S. citizen parents without knowing it. If at the time of the person’s birth his parent or even grandparent was a U.S. citizen, the person should obtain immigration counsel to analyze the laws governing acquisition of citizenship. (Charts outlining elegibility for derivation and acquisition of U.S. Citizenship can be found in Ira J. Kurzban, Kurzban's Immigration Law Sourcebook Appendix B (8th Ed. 2002), and Katherine A. Brady, California Criminal Law and Immigration Appendix 9-B (1999 Ed. With 2000 update).)      A second way that many persons are citizens without knowing it is through derivation of citizenship. A child automatically becomes a U.S. citizen if, before he reaches the age of 18, the following three events happen in any order: (1) he becomes a permanent resident, (2) at least one of his parents becomes a U.S. citizen, and (3) he lives in the United States in that parent’s legal and physical custody. (See 8 U.S.C. § 1431. This rule applies to adopted children as well. An adopted child automatically becomes a U.S. citizen if, while under the age of 18, she (1) becomes a permanent resident; (2) is legally adopted by a U.S. citizen before she reaches the age of 16, and has resided at any time in the legal custody of the U.S. citizen for two years; and (3) is residing in the legal and physical custody of the U.S. citizen parent.)      Where a child is a permanent resident, encourage a parent who has custody to naturalize to U.S. citizenship. If this occurs before the child’s 18th birthday, the child will become a U.S. citizen automatically, without having to prove that she has good moral character or meet any other requirement, and will be made safe against immigration consequences of any adult convictions that she may receive in the future. See Appendix F for more on citizenship.