one must be a Permanent Resident (green card holder) for five years
prior to applying for U.S. Citizenship. Persons married to a U.S.
Citizen spouse can apply in three years. In addition to being eighteen
years or older, there are continuous residence requirements limiting
the length and duration of overseas stays, physical presence requirements
during the three or five year period, and a three month in state
residency requirement. The applicant must show good moral conduct
by complying with criminal and tax laws. Lastly, the applicant must
pass a civic and history examine at the interview while demonstrating
their proficiency in the English language.