You meet the requirements for U.S. citizenship if you are at least 18 years old, pass a U.S. history and civic test, be of good moral character, and be able to read, write, and speak basic English. In addition, you must meet one of the several requirements: be a lawful permanent resident (with a green card) for 5+ years, lawful permanent resident for 3+ years if married to a U.S. citizen, or an active/retired U.S. military service member. To determine your eligibility, reference this test by the USCIS.