Obtain a copy of your birth certificate from the health department. Contact the health department in the county of your birth for an official copy of your birth certificate. This is the primary document to prove citizenship.
Use your naturalization certificate to prove citizenship. If you are born outside of the country but take the legal steps to become a citizen, a naturalization certificate is granted. Naturalization certificates are legal proof of citizenship.
Present a Consular Registration of Birth Abroad certificate to prove citizenship. If your parents registered your birth with a U.S. Consulate in the first five years of your life, a certificate called a Consular Registration of Birth Abroad is presented.
Apply for a passport or Certificate of Citizenship. If you were born abroad to legal citizens of the U.S. but no record of your birth was registered with the U.S. Consulate, you need to apply for a passport or Certificate of Citizenship. You'll need to provide proof of citizenship and residency for your parents. Use their birth certificates and marriage documents, as well as tax documents as proof. Supply your birth certificate and proof of your identity.