Each year the USCIS naturalizes approximately 680,000 citizens and so far over 6.8 million citizens have been naturalized into the United States. This fiscal year alone the US has already naturalized 495,232 people.
To apply for naturalization an individual must fill out Form N-400 (Application for Naturalization) and fulfill the requirements of the Immigration and Nationality Act (INA). The INA sates an applicant must be at least 18, a green card holder, have resided in the US for at least five years, physically present in the US for at least 30 months, have good character, understand U.S. government & history, comprehend the English language and take the Oath of Allegiance.
Some exceptions exist for the naturalization requirements for individuals who are members of the military and whose spouses are U.S. citizens. Some of these exceptions include spouses, who may be eligible to receive naturalization in three years after being permanent residents rather than five, spouses stationed abroad may not have to meet residency requirements, children under 18 who are permanent residents can automatically gain citizenship if living with a U.S. citizen parent, and children living abroad with at least one U.S. citizen parent physically in the U.S. can be eligible for naturalization.
Individuals that have been naturalized live primarily in these 10 states: California, New York, Florida, Texas, New Jersey, Illinois, Virginia, Massachusetts, Washington and Maryland.