Your ancestor's Certificate of Naturalization or his Italian passport and "Alien Registration Card" ("green card").

If your father became a US citizen but his Certificate of Naturalization is not available: you must provide the following:

a) Official statement (in original, not photocopy, and with the Office Seal) from the US Immigration and Naturalization Services in Washington D.C. (425 I Street NW, 2nd Floor - ULLICO Bldg, Washington, D.C. 20536) and from the Court County in which he resided, stating the number of the Certificate of Naturalization and the date of his naturalization. The statement must show your father's full name (and any other names he/she went by on any official documents), place of birth and date of birth, date of the naturalization, certificate number; if he never became a US citizen, you have to show his Italian passport and Alien Registration Card.

b) IF THE RESEARCH SHOWS NO RECORD: you are requested to double check with the National Archives (www.nara.gov) requesting a full search under his name and nicknames, possible dates of birth which he may have declared in the course of his life. If the record is found, you will obtain from the National Archives a certified copy of his "petition for naturalization" and "oath of allegiance" (Please note: this Office may at any time request that you present documentation from the National Archives - in case of discrepancies - to confirm the identity reported on the certificate of naturalization).

c) If the record is still negative, you may want to check with the "CENSUS", requesting a survey report dated after your date of birth (www.census.org);