Commonly articulating, a man can become a U.S. resident in one of four channels. Principal, by being born in the United States or one of its boundaries. Next, if you were born to parents who are U.S. nationals, then you may be a U.S. national yourself. This means is named the "acquisition" of citizenship. Three, you can be a national by the adoption method, which commonly includes petitioning for, and taking, a citizenship examination. Finally, you may be a national if one or both of your progenitors have been adopted. This is named "descent" of citizenship.