One of the following documents is required to show proof of U.S. Citizenship:
Copy of birth certificate
U.S. passport
Wallet-sized U.S. passport card
Certificate of Naturalization (N-550 or N-570)
Certificate of Citizenship (N-560 or N-561)
Forms FS-240 (Consular Report of Birth Abroad), FS545 (Certificate of Birth Issued by a Foreign Service Post), or DS1350 (Certification of Report of Birth)