How to Find Naturalization Records and Citizenship Files from the 1930s

1. Master the "Two-Paper" Process

Citizenship in the 1930s was not a single event; it was a process that took several years and generated multiple distinct documents.

• The Strategy: You must search for both the "First Papers" and the "Second Papers." Do not stop searching just because you found one of them.

• The Breakthrough: The Declaration of Intention (First Papers) was filed shortly after the immigrant arrived, officially stating their desire to become a citizen. The Petition for Naturalization (Second Papers) was filed at least two to five years later. Because immigrants frequently moved during this waiting period, the First Papers might be filed in a New York court, while the Second Papers could be filed in an Ohio court. You can track this migration by finding the ancestor in our Census & Population Collections.

2. Hunt for the 1929 Photographic Bonus

One of the most incredible, yet least-known facts about 20th-century citizenship files is that they can put a face to your ancestor's name.

• The Strategy: If your ancestor filed a Declaration of Intention or received a final Certificate of Citizenship during or after 1929, immediately request the original, physical file from the National Archives (NARA) or the USCIS Genealogy Program.

• The Breakthrough: Starting in 1929, the federal government required immigrants to submit a passport-style photograph with their Declaration of Intention. For many genealogists, pulling a 1930s naturalization file is the very first time they ever see a photograph of their immigrant great-grandparents.

3. Use the "Certificate of Arrival" to Find Their Ship

If you are struggling to find the ship that brought your family to America, a 1930s citizenship file will do the work for you.

• The Strategy: Look for a small, half-page document clipped inside the Petition for Naturalization called the Certificate of Arrival.

• The Breakthrough: In the 1920s and 1930s, the government refused to grant citizenship until federal clerks actively verified the immigrant's legal entry. Clerks would dig through the old port records and issue a Certificate of Arrival, which explicitly lists the port of entry, the exact date of arrival, and the name of the vessel. Once you have this certificate, you can easily jump to our guides on Searching Early 1900s Ellis Island Lists or Finding Your Ancestor's Ship to pull the original manifest.

4. Search the Federal District Courts

While early immigrants filed for citizenship in local county courthouses, by the 1930s, the vast majority of naturalizations took place in Federal District Courts.

• The Strategy: If a statewide search of local county records comes up empty, shift your search to the federal level by accessing the National Archives (NARA) regional branches.

• The Breakthrough: NARA holds millions of digitized, highly detailed Petitions for Naturalization from the federal courts. When searching these federal indexes, use the most formalized version of your ancestor's American name, as 1930s judges often legally formalized an immigrant's name change (e.g., officially changing "Giuseppe" to "Joseph") during the final oath ceremony.