Citizenship of the United States
A person who is considered a citizen by more than one nation has "dual citizenship". It is possible for a United States citizen to have dual citizenship; this can be achieved in various ways, such as by birth in the United States to a parent who is a citizen of a foreign country (or in certain circumstances the foreign nationality may be transmitted even by a grandparent) by birth in another country to a parent(s) who is/are a United States citizen/s, or by having parents who are citizens of different countries. Anyone who becomes a naturalized U.S. citizen is required to renounce any prior "allegiance" to other countries during the naturalization ceremony; however, this renunciation of allegiance renunciation of citizenship to those countries.
Citizenship of the United States
Non-citizen nationals of the United States may reside and work in the United States without restrictions, and may apply for U.S. citizenship under the same rules as permanent U.S. residents. Both of these groups are not allowed to vote in federal or state elections, although there is no constitutional prohibition against their doing so. Every national of the United States statutorily transmits nationality to children born outside the United States.