• Rules for citizenship in the United States vary, depending on a person's circumstances of birth or application for citizenship as an adult. While any child born within the United States is automatically granted American citizenship, children born abroad to American parents are granted citizenship under certain conditions. The United States also naturalizes immigrants who demonstrate that they're willing to learn the foundations of American government and abide by U.S. laws.
  
  

Children Born Outside the United States

• Since May 24, 1934, the duration of an American's residence in the United States before becoming the parent of a child born overseas has been the basis for determining his child's citizenship. The parent's residency requirements have changed four times since 1934 and, as of November 2010, a child born abroad to an American parent gains automatic citizenship if his American parent lived within the United States for five years before his birth. The child's American parent must also have resided in the United States for two years after turning 14. Prior to May 24, 1934, any child born abroad to an American father was automatically granted U.S. citizenship, though Congress had to pass retroactive legislation in 1994 to grant that right to children born abroad to American women.
  
  

Becoming a Naturalized Citizen

• A prospective U.S. citizen must reside within America for five years after she applies for citizenship and live in her home state for at least three months. If she leaves America for more than six consecutive months, she must reapply for citizenship. She must demonstrate good moral character, and her application will be denied if she's convicted of crimes involving gambling, prostitution or drug offenses. Nobody convicted of murder or an aggravated felony can become a naturalized citizen. She must be fluent in English, able to speak and read words used in ordinary communication, and must know fundamental U.S. history and the principles of American government. To complete the naturalization process, she must swear the Oath of Allegiance in a U.S. district court.
  
  

Foreign-Born Spouses of American Citizens

• A foreign-born U.S. resident married to an American spouse may be granted citizenship within three years of her application. Her spouse must meet all U.S. citizenship requirements, and she must have been married to him for at least three years before applying for citizenship. The U.S. may waive residency requirements for a foreign national married to an American spouse who has lived abroad for the duration of her marriage under certain conditions -- e.g., the spouse is employed by the U.S. government or military, a U.S. research institute or a religious group recognized by the American government.