Finding Your Ancestor’s WWII-Era Alien Registration Form

This is the third post in my new blog series about researching your 20^th century U.S. immigrant ancestors’ alien registration documents. If you did not yet read part one or part two, you want to consult those posts first. This third post focuses on how to find and request your ancestor’s Alien Registration Form.

---

How the INS Processed the Forms

Following passage of the Alien Registration Act of 1940, the U.S. Immigration and Naturalization Services (INS) created the Alien Registration Division to oversee the new Alien Registration Program. The division reviewed and processed all AR-2 Forms sent to the INS. They assigned a unique Alien Number – also called an Alien Registration Number, often abbreviated as A#, AR#, or A-Number) to forms approved as complete, coded them, and microfilmed them. The new division was also charged with creating and maintaining a searchable index of the AR-2 Forms. The INS disbanded the Alien Registration Division on 31 December 1944 and the INS forwarded the original AR-2 Forms to its field offices.¹ 

Where to Obtain the Records

These World War II (WWII) era Alien Registration (AR-2) Forms can be obtained from the U.S. National Archives and Records Administration (NARA) or from the U.S. Citizenship and Immigration Services (USCIS). We always want to check NARA first since we can now search for these files online there.

The Flexoline Index at NARA

Start by consulting the Flexoline Index, which became publicly available and searchable in NARA’s Access to Archival Databases (AAD) tool in May 2024. 

About the Flexoline Index

The Flexoline Index is the manually-keyed index initially created as a paper index by the Alien Registration Division. Different subsequent versions of the initial AR-2 Alien Registration Forms were added to this index.

The original Flex records were strips of ticker tape-like paper pasted onto a carrier sheet. These sheets were microfilmed and later manually keyed into a searchable, electronic database. After conversion, the Flex digital images and database were managed by INS, later United States Citizenship and Immigration Services (USCIS), as a component of the Microfilm Digitization Application System (MiDAS).²

USCIS transferred the WWII-era Alien Registration and the Flexoline Index to NARA custody as of 17 May 2024. NARA created a new database out of the index and images that allows NARA archivists to search the database and find your WWII-era AR-2 Form. These records and the database are in the custody of the Electronic Records Division of NARA based at the College Park, Maryland (Archives II) facility. A public-facing version of that Flexoline database is available in NARA’s AAD, which allows researchers to search for people born more than 100 years ago. The public searchable database does not include access to digitized AR-2 Forms, but those records can be ordered.

We genealogists all need to thank Records, Not Revenue for galvanizing the community to keep the pressure on USCIS to transfer immigration records, like these WWII-era AR-2 Forms, to NARA custody.

About the AAD

The Access to Archival Databases (AAD) is one of the research discovery tools for identifying and accessing historical record series in the custody of NARA. The AAD does not index and search among all record groups held by NARA though. It indexes and searches across just a subset of records held by NARA, electronic records that NARA acquired from other federal government agencies for permanent preservation. These are “born-digital” historical records or indexes stored in databases created by federal agencies. NARA explains: “There are databases and indexes from more than 30 archival series, including over 350 data files totaling well over 50 million unique records; this number will continue to grow. Search by person, geographic areas, organizations, or dates.”³

Searching the Flexoline Index

You want to consult that public-facing Flexoline Index in NARA’s AAD to look for ancestors in that new database (Flexoline Index Data File, 1940 – 1955). However, I recommend using the Fielded Search tool instead of the default Basic Search tool or even the Advanced Search tool because it allows better precision through faceted search filters..

The image above in Figure 2 shows the home page to the Flexoline Index public database in NARA’s AAD. Marked by me in the red frame, we see the AAD item record tells us that there is one record series in this particular AAD database, the Flexoline Data File, 1940 – 1955. Every AAD database has Basic Search and Advanced Search (A) tools. The binoculars icon marked Search (B) is the Fielded Search tool that I recommend.

The Fielded Search tool in Figure 3 allows us to search the Flexoline Index database by different pieces of information about our ancestors. The view above is the default Fielded Search tool that references the individual’s given name and surname (A), Alien Number (B), state in which they registered as an alien and their country of birth (C). Notice that the state and country fields (C) include a “NARA added” notation. That means the information in those fields are values that NARA archivists entered into their version of this database, instead of those fields containing the values from the INS/USCIS version of the Flexoline database. In their FAQ document about the Flexoline Index in AAD, NARA explains that the INS/USCIS database had inconsistent coding in those original fields so NARA created new versions of these fields to clean up the data.⁴ The “Show More Fields” button (D) displays more options.

Clicking on the “Show More Fields” button in the Fielded Search tool (see: Figure 3) brings up all options you can use to search for your ancestor’s WWII-era Alien Registration (AR-2) Form (see: Figure 4). You can select whichever fields you want to try. If you know the city or at least the county in which your ancestor lived when they would have registered as an alien, narrowing your search results to just that city (A) or county (B) can be helpful. I use the “NARA added versions of those fields.” My 20^th century Mexican immigrant ancestors immigrated with their extended families and settled together in the same counties and sometimes cities. So I always use these field when I want to identify any possible collateral relatives with the same surname living in the same area at the time of Alien Registration.

You have the best chance of success at finding the WWII-era Alien Registration (AR-2) Form for your ancestor if you already know their unique Alien Registration Number, particularly if they have a common name. In Figure 5, I am searching the Flexoline Index for the known A-Number for my great-aunt Guadalupe (Robledo) Perez.

Searching for great-aunt Guadalupe (Robledo) Perez by her Alien Number brings up three separate entries for her in the Flexoline Index (see: Figure 6). Note that all three entries reference the same A-Number for someone born in Mexico in 1910. Only one entry references the city and state in which she registered. She was indexed by the INS under her given name Guadalupe (misspelled as “Guadalu” in the index), her nickname, Lupe, her maiden name Robledo, her married name Perez, and those two surnames combined. If you do not have their A-Number, you want to search for your ancestor using all variations and combinations of their given names, nicknames, and surnames.

The item record for Guadalupe in Figure 7 does not provide us with much biographical information. However, it can sometimes help us determine if the person is the one we are looking for, especially if you do not have their A-Number. The new information we learn about Guadalupe from this item record versus just the search results list is her middle initial, date of birth, and year of last arrival to the United States. We can us that information to check against other records to determine if this is the right person. 

What we do not get in these item records is a digitized copy of the AR-2 Form. Those are not available in the public-facing version of the Flexoline Index, only in the version available to NARA archivists. However, we can request the digitized form by providing the archivists with information from these item records.

Requesting the Record

Once you have identified your ancestor in the Flexoline Index database, you need to email the NARA Electronic Records Division to request the digitized AR-2 Form. That email address can be found on the “home page” for the Flexoline Index database in the AAD, under the Location field in the Series Description notes: cer@nara.gov.

For Your Email Request

Your email request to the archivist should include: 

• The alien’s name (I include variations too)
• Their country and date of birth
• Their Alien Number
• The Flexoline DID (Document Identifier field at the top of the item record in Figure 7)
• Arrival year
• Residence state when registered

Your request must include 

• Your first and last name
• Your billing or shipping address
• An indication if you want a PDF copy or a certified copy

You will receive a confirmation receipt of your email request right away. Then I usually get a personal reply from an archivist within a couple business days notifying me of the results of their search, a quote to obtain the digitized AR-2 Form, and payment instructions.

Reproduction Costs

The fees are documented on this NARA web page but currently run:

• $20 for a single AR-2 Form in PDF format
• $17 for a PDF of each additional AR-2 Form requested (up to 10 max)
• $15 extra for a certified copy of an AR-2 Form.

I usually receive a PDF image of the AR-2 form via email within one or two business days after submitting my payment.

Restrictions & Challenges

The publicly-searchable version of the Flexoline Index only includes people born more than 100 years ago due to privacy restrictions. If you are looking for the WWII-era Alien Registration (AR-2) Form for someone born 100 years ago or less, they will not show up in this database. However, you should still contact the NARA Electronic Records Division to inquire if that record is in their custody. Those requests are handled as a FOIA (Freedom of Information Act) request and require documentary proof of death of the individual.

Acceptable forms of proof of death include: published obituary, a copy of death certificate, letter from a funeral home, or documentation from another recognized source, such as: Ancestry or the Social Security Death Index. Any proof of death documentation must include the name of the deceased individual, the birth date and the date of death.⁵

Another challenge is that the public-facing Flexoline Index includes extracted information and item records for Alien Registration Forms that have not yet been transferred by USCIS into NARA custody. My next blog post in this series will discuss this situation more.

Finding Alien Numbers

As mentioned already, you have the best chance of success at finding the WWII-era Alien Registration (AR-2) Form for your ancestor if you already know their unique Alien Number. Following are documents on which we find the Alien Registration Number for my great-grandmother Maria (Nieto) Robledo. She was the mother of my great-aunt Guadalupe (Robledo) Perez. I am showing you Maria’s documents instead of Guadalupe’s because of complications Guadalupe faced when she tried to begin the naturalization process, which I will discuss in the case study I am teaching for Legacy Family Tree Webinars in November.

Naturalization Papers

I frequently find Alien Registration Numbers on U.S. naturalization documents. This could be either set of naturalization papers if the immigrant had not already naturalized before the 27 August 1940 effective date for the Alien Registration Program. 

My great-grandmother Maria (Nieto) Robledo – Maria Nieto Compeán in Mexico – registered as an Alien on 8 November 1940 and naturalized as a U.S. citizen on 24 January 1955.⁶ The Petition for Naturalization she filed on 2 December 1954 includes her Alien Registration number typed in a designated field on the bottom left corner of the front of the form (see: Figure 9). We sometimes see AR#s handwritten on these documents before the government started included a designated field.

Border Arrival Records

I also often find Alien Numbers on U.S. border arrival records from Mexico. This includes manifest cards and manifest sheets. Since I do not work with border arrival records from Canada or ship passenger lists in the 20^th century, I cannot say if you should find A-Numbers on those documents. But my suggestion is that you check.

My great-grandmother Maria (Nieto) Robledo – Maria Nieto Compeán in Mexico – immigrated to the United States on 27 October 1915 at the Laredo, Texas port of entry.  She accompanied her infant son Refugio Robledo.⁷ We can see in Figure 10 that someone – likely an INS field agent at Laredo – later wrote Maria’s Alien Registration Number on her border manifest card.

The New Ancestry Database

Ancestry released its version of the public-facing Flexoline Index database in 2025, pulling their data from the AAD database at NARA. You can search this database like the AAD version to locate who you think is the right ancestor and find their assigned Alien Number. These index records also show up as record Hints, which facilitates discovery. Use the A-Number that you find in this database to then go search NARA’s Flexoline Index before sending your request to NARA’s Electronic Records Division. I always link to the Flexoline Index item record in the requests I email to the archivist.

Learning More

In the next post of this blog series, I will share my workflow for checking on an additional type of record series that contains these WWII-era Alien Registration (AR-2) Forms along with more genealogy gold mine documentation as well as my next steps if I cannot find an AR-2 Form with NARA.

Aunt Guadalupe went through a complicated pathway towards obtaining U.S. citizenship. I teach a case study about her immigration records in an upcoming webinar for Legacy Family Tree Webinars, “Taking a Deep Dive into Mexico – U.S. Border Crossing Records“. The webinar is scheduled for Friday 20 November 2026 at 11:00 am Pacific. The live webinar is free, however, registration is required. An annual membership to Legacy Family Tree Webinars ($49.95) gains you access to the handout and the entire library of recorded genealogy webinars. REGISTER TODAY to save your seat for this upcoming webinar.

This post or page contains affiliate links for products and services I personally use and recommend. See Disclaimers & Disclosures.

Additional Resources

• U.S. National Archives and Records Administration: Alien Registration (AR-2) Forms
• U.S. National archives and Records Administration: Frequently Asked Questions (FAQs): Flexoline Index Database [Public Use Version], ca. 2000–ca. 2003
• U.S. National Archives and Records Administration: 2025 Genealogy Series – Researching Immigrant Ancestors: Alien Registration (AR-2) Forms
• Records, Not Revenue: AR-2 Forms and the Flexoline Index

Sources