Bases for Citizenship

There are two fundamental principles on which the United States recognizes citizenship: jus soli, (translation for those who don't speak Latin or Lawyer: right of birthplace), and jus sanguinis (translation: right of blood).  If a person is born in the United States, under jus soli they are considered an American citizen regardless of the country their parents are citizens of.  Conversely, jus sanguinis entitles automatic citizenship children born to at least one United States citizen, anywhere in the world.