Route the search by date, court, and record series.
- Before September 27, 1906, naturalization could occur in federal, state, county, or municipal courts.
- For later historical files, USCIS may hold C-Files or A-Files while the National Archives may hold the creating federal court’s declaration and petition.
- State and local court records can remain with a county clerk, state archive, historical society, or another local custodian.
- A negative search from one repository proves only that the repository did not locate a record in its custody.
Official sources for this guidance
- Naturalization records — U.S. National Archives
- Form G-1566 instructions — U.S. Citizenship and Immigration Services
Give every repository a search-ready profile.
- Full name and known spelling variants.
- Date and place of birth.
- Approximate arrival and naturalization dates.
- Residence at the likely time of naturalization.
- Known court, petition, certificate, alien, or census references.
Official sources for this guidance
- Naturalization records — U.S. National Archives
- Form G-1566 instructions — U.S. Citizenship and Immigration Services
A declaration is not necessarily the final event.
Citizenship analysis should use the record that establishes whether and when naturalization was completed. This guide is general information, not legal advice. Access rules, forms, fees, and processing conditions can change; verify the current instructions with the issuing office before ordering.
Official sources for this guidance
- Naturalization records — U.S. National Archives
- Form G-1566 instructions — U.S. Citizenship and Immigration Services
Questions to resolve before you act
Why can’t I search only USCIS?
USCIS does not hold every pre-1906 court record, and NARA or state and local repositories may hold other parts of the naturalization file.
Does a NARA negative search prove the person never naturalized?
No. NARA states that a negative search covers only its holdings. USCIS has the authority to issue a Certificate of Non-Existence for records in its custody.
What information makes a search stronger?
Name variants, birth details, arrival period, residence, approximate naturalization date, and the possible court help identify the correct collection.
Verify before filing
These official sources were used for the factual review. Open the live instructions before ordering a record or submitting an application.
- Naturalization recordsU.S. National Archives
- Form G-1566 instructionsU.S. Citizenship and Immigration Services