http://www.uscis.gov/portal/site/usc...00b92ca60aRCRD[QUOTE

Bases for Citizenship: Birth, Blood, or Naturalization The U.S. recognizes citizenship according to two fundamental principles: jus soli (right of birthplace), and jus sanguinis (right of blood). Under jus soli, a person receives American citizenship by virtue of being born in the United States. By contrast, jus sanguinis confers citizenship on those born to at least one U.S. citizen anywhere in the world. A person who does not qualify under either of these principles may seek U.S. citizenship through the process of naturalization.][/quote]


ETA; If that isn't good enough, check the link,