Birthright Citizenship and Acquisition or Derivation of Citizenship Through Parents
If you were born in the U.S. or in a U.S. territory, you likely have birthright citizenship in the U.S. (There is an exception for children of foreign government employees who held diplomatic status in the U.S.) Other ways to get U.S. citizenship include acquisition and derivation. Acquisition means that you were born to a U.S. citizen parent. Derivation means that your parents were not U.S. citizens when you were born, but at least one parent later became a U.S. citizen. If you do not fit within the categories of birthright citizenship, acquisition, or derivation, you will need to go through the naturalization process to get U.S. citizenship. This involves completing an application and passing various tests imposed by USCIS.
You may not be aware that you are a U.S. citizen, especially if you have spent most of your life in a foreign country. If you were born in the U.S., for example, you will remain a U.S. citizen even if you do not live in the U.S. and if you engage in civic activities in other countries, such as voting in their elections. Birthright citizenship remains valid for life unless you choose to renounce it. If you are interested in pursuing legal status in the U.S., it is worth checking to see whether you may be a citizen already. You should make sure to get a Certificate of Citizenship (or potentially a passport) to prove your citizenship if you successfully establish a claim to it. You are a U.S. citizen regardless of whether you have this document, but you have no proof of citizenship without it. Read more here about getting proof of citizenship.
Acquisition of Citizenship
As discussed above, this may apply when a child is born in a foreign country to a parent who is a U.S. citizen when the child is born. Since immigration laws controlling acquisition of citizenship have changed over time, it may be challenging to determine whether a certain child has acquired citizenship. This would depend on the law that applied when the child was born. It also might depend on the law that applied when the child’s parents were born if the acquisition of citizenship is affected by the U.S. citizenship of the child’s grandparents. Different laws applied before May 24, 1934, between May 35, 1934 and January 12, 1941, between January 13, 1941 and December 23, 1952, between December 24, 1952 and November 13, 1986, and since November 14, 1986. Read more here about acquisition of citizenship before 1986, and read more here about acquisition of citizenship after 1986.
Someone who has U.S. citizenship through acquisition will pass their U.S. citizenship to any children as well.
Derivation of Citizenship
If you are under 18 and hold a green card, you may get U.S. citizenship automatically if a parent becomes a citizen. You would need to live with that parent at the time that they become a citizen. If you get U.S. citizenship through derivation, you do not need to participate in a naturalization ceremony.
As with citizenship through acquisition, different laws have applied to citizenship through derivation over the years. The law for your situation will depend on whether your parent became a citizen before May 24, 1934, between May 24, 1934 and January 12, 1941, between January 13, 1941 and December 23, 1952, between December 24, 1952 and October 4, 1978, between October 5, 1978 and February 26, 2001, or on February 27, 2001 or later. Read more here about derivation of citizenship.