On Wednesday, March 25th I am hosting and teaching a FREE WEBINAR to learn about the original U.S. population census manuscript records. Because I am teaching this for my day job library at the Pollak Library at California State University Fullerton (CSUF), this webinar will have more of an academic focus than a genealogy one and will highlight how the U.S. census has changed over time and has (or has not) counted POC (People of Color). However, genealogists and family history curious people will also benefit from this webinar. Registration is required.

If you are a professor who offers extra credit, please consider doing that for this event.

America at 250: The Historical Census Manuscripts

• Date & Time: Wednesday, March 25, 2026 (4:00-5:30 pm Pacific Time)
  • Presentation 4:00-5:00
  • Extended Q&A: 5:00-5:30
• Format: Webinar on Zoom
• Registration: FREE and open to the public, but registration is required.

The federal decennial census has been conducted every 10 years since 1790, creating a snapshot in time record mandated by the U.S. constitution and Congress. Who has been counted and named in each census and the questions asked in each census have varied over time. The manuscripts pages are the handwritten forms containing names and personal information. They bring to life the numbers reflected in the aggregated data with which most academics and government officials work and serve as rich sources for studying communities, families, and individuals over time. Learn how to access and analyze the manuscripts for your research and scholarship, and hear how CSUF faculty have integrated these into their curriculum.

The post My Free U.S. Federal Census Webinar March 25 appeared first on Colleen Robledo Greene.

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

The post Finding Your Ancestor’s WWII-Era Alien Registration Form appeared first on Colleen Robledo Greene.

This is the second 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, you want to consult that post here first. This second article focuses on the information you can learn about your immigrant ancestors and their family from a World War II-era Alien Registration (AR-2) form.

All applicable aliens living in the United States on the designated date registration was scheduled to begin on 27 August 1940 were required to register in person at their nearest first or second class post office or other registration place designated by the Immigration & Naturalization Service (INS). They had to register by 26 December 1940. A parent or guardian for those under age 14 had to register in person for that minor.¹ Registration was done on form AR-2, an Alien Registration form that consisted of 15 groups of questions.

The Registration Process

The designated registration officer at the post office filled out the AR-2 form with information provided to them by the alien or the parent or guardian of any alien under the age of 14. The registering officer took a complete set of fingerprints for the INS, although only the print of the right index finger was attached to the AR-2 form. The alien registrant had to personally sign and swear to or affirm the accuracy of the information they provided to the registration officer. If they could not sign their name, the individual had to make their mark in front of a witness, and the witness signed their name and address near that mark.²

Registration officers sent the AR-2 forms to the INS in Washington, D.C. The Alien Registration Act of 1940 stated that the information submitted by the alien on the form would remain secret and confidential, made available only to individuals and government agencies approved by the INS Commissioner and the U.S. Attorney General.³ The INS assigned and stamped a unique Alien Registration number on the top left corner of the front of the AR-2 form and sent the registered alien a receipt card (AR-3 form) with their new Alien number.

Analyzing the AR-2 Form

To thoroughly analyze and understand a WWII Alien Registration (AR-2) form, we need to look beyond the form. We need to consult the instruction manual issued by the Immigration & Naturalization Service (INS) Alien Registration Division to carry out Title III of the Alien Registration Act of 1940.⁴

We will dissect each part of the World War II-era Alien Registration form for my great-aunt Maria Guadalupe “Lupe” (Robledo) Perez. To avoid a long list of footnotes repeatedly citing this same AR-2 form as we walk through each part of the form, I am citing that single historical document once here.⁵ Each section of information about Guadalupe that I am extracting from this AR-2 form is marked with italics so that it is easier to distinguish from the information we learn about that section of the form from the instruction manual.

Form Header & Footer

This is the front page of the AR-2 Alien Registration form for Guadalupe. The INS stamped her unique Alien number (also called an Alien Registration number) 2752504 on the top header after receiving this form from her post office.

The footer on the back of Guadalupe’s AR-2 form tells us that she registered as an alien on 9 October 1940 in Glendale, [Los Angeles County], California, likely in the Glendale post office. She signed her name Guadalupe Mary Perez and we we see her fingerprint.

Question Groups 1 & 2: Names & Residence

Guadalupe’s current legal name was Guadalupe Mary Perez. She first entered the U.S. under the name Guadalupe Robledo, which was her maiden name. She was also known by the nickname Lupe. Gudalupe lived at 2322 North Verdugo Road in Glendale, Los Angeles County, California and regularly received her mail from the Glendale post office.

Although questions 1A and 1B on the form do not tell us this is Guadalupe’s current legal name in 1A and the name under which she first arrived in the U.S. in 1B, the Alien Registration Division instruction manual make this clear.

The alien shall give in full his present legal name. He shall also give the name under which he first arrived in the United States, as it was spelled at the time of arrival. The alien shall list all the names by which the alien has ever been known, either in the United States or outside, including the maiden name of married women, the original name or name or names of an adopted child, business, or professional name, aliases and nicknames. If the alien is under fourteen years of age, then his mother’s maiden name shall be listed. All names given by the alien shall be in the English alphabet.⁶

The manual informs us that question 2A pertains to “the place where the alien habitually sleeps” and that the registering alien must state if they do not have such a place. The post-office question in question 2B pertains to “where his mail is regularly received or delivered.”⁷

Question Groups 3 & 4: Birth & Citizenship

Guadalupe was born 30 June 1910 in or near Guamuchi in the state of San Luis Potosí, Mexico, and she was a citizen of Mexico.

Regarding the birth information in question group 3:

The alien shall state the month, day, and year of his birth according to the American (that is, Gregorian) calendar. He shall also state the city, town, or village of his birth, as they existed at the time of birth [emphasis added by me]. The alien shall name as the country of his birth the state or power which, at the time of his birth, exercised dominion and sovereignty over the place of his birth.

Question 4 asked the country in which the registrant was a citizen or subject. The manual explains that if the registrant is no longer a citizen of any country, they needed to list “the country of which he was last a citizen or subject, or to which he last owed allegiance.”⁸

Question Groups 5 & 6: General & Physical Info

Guadalupe was described as female, married, and of the (Other) Mexican race. She stood 5 feet 1 inch tall, weighed 140 pounds, and had black hair and brown eyes.

Regarding marital status, the manual states “If the alien is separated from his or her husband or wife, but not divorced, he shall be listed as married.”⁷ I mentioned in the first blog post that I think the term alien is dehumanizing. The way in which the Alien Registration Division instructions address how to report the race of the registrant is dehumanizing as well.

The alien shall state the race to which he belongs. Persons of mixed blood shall not be considered members of the white race; they shall be considered as belonging to the racial stock other than white from which they may have sprung. Persons sprung from more than one racial stock other than white shall list themselves as “Other” as of mixed blood. Hindus shall be listed under “Other” as Hindus.⁷

Question Groups 7 & 8: U.S. Immigration Status & Residency

Guadalupe reported that she last arrived in the U.S. in October 1915 at the Laredo, Texas port of entry, but she was uncertain of the exact date. She arrived by train as a passenger and entered the U.S. as a permanent resident. Lupe first arrived in the U.S. in October 1915, which although not stated here was likely the same arrival event. If she had visited her home country of Mexico since immigrating in 1915, those visits were under six months. She reported that she had lived continuously in the U.S. for 25 years, which aligns with her 1915 immigration year.

Last Arrival in the U.S.

The Alien Registration Division of the INS required quite a bit of information pertaining to what it defined as the date of last arrival into the U.S for question 7A . First, they defined date of last arrival from the point of an alien who had been in the U.S. before, then left the U.S., and later returned to the U.S. The INS applied a geographic criteria to that:

• If the individual returned from a visit to Mexico or Canada that lasted less than six months, that return date of arrival was not considered their last date of arrival. This implies that returning from a visit to Mexico or Canada that lasted six months or longer qualified as a new last arrival event.
• Individuals returning to the U.S. from a visit of any length to a different country than Mexico or Canada, however, had to report that date of entry as their new last arrival date.

The final questions (7B & C) pertaining to their date of last arrival dealt with the mode of transportation the individual used to enter the U.S. and their immigration classification (7D). If the individual arrived by boat, they had to provide the name of the ship or at least the shipping line if they could not remember the name of the ship.

Although this section of the instruction manual does not directly state that individuals who entered the U.S. only once needed to report that single arrival date as their last arrival, we see from Guadalupe’s AR-2 form that was the procedure.

First Arrival

In question 7E, the individual reported their official date of first arrival to the U.S. However, what the INS classified as the official date of first arrival does not necessarily reflect the first time an immigrant came to the U.S. The instruction manual defined the first arrival as “the earliest arrival following which the alien remained for six months or longer.” So stays in the U.S. for less than six months did not qualify as the date of first arrival.

Residency

In question 8A, the individual had to report the total number of years they lived in the U.S. since first arrival (question 7E). The date of first arrival started the residency clock. If the registrant had traveled outside the U.S. any number of times for trips of less than six months, that time abroad could still be counted towards residency. If any trips abroad lasted six months or longer, that time had to be deducted from what they reported here as a years of residency. For question 8B, the manual states: “The alien shall also state whether he intends to stay in the United States permanently, and if not, how long he expects to stay.¹¹

Question Group 9: Occupation

Guadalupe usually worked as a housewife. However, she presently did factory work for the Derick Paine L.A. Basket Company, a basket manufacturer located at 1295 Los Angeles Street in Glendale.

The instruction manual indicates the registrant needed to state their usual occupation, “the trade, business, or profession by which the alien ordinarily earns his livelihood.” They also needed to report their present occupation, the name and address of their current employer, and the type of business or industry. If the registrant owned their own business, they had to state this along with their business address.⁷

Question Groups 10 & 11: Organizations & Military Service

Guadalupe reported that she had no organizational affiliations within the past five years. She also stated that she had no prior military service in the U.S. or any other country.

Question 10 required the registrant to “state any activities in addition to his occupation which he is, has been within the past five years, or intends to be engaged.” This included naming any “clubs, lodges, groups, organizations or societies” in which they participated, held a membership, or served as an official. The registrant was required to report in question 11 if they had served in the armed forces or auxiliary arms of service of the U.S. or any other country, and if so, which country, branch of service, enlistment date, and discharge date. They also needed to indicate if they had served as a mercenary.¹³

Question Groups 12 & 13: U.S. Naturalization & Relatives

Guadalupe stated she had not applied for first citizenship papers, a declaration of intention to start the process of naturalizing as a U.S. citizen. She indicated that she had one living parent, a spouse, and one child living in the U.S.

Question 12 pertains to U.S. naturalization status. The registrant needed to indicate if they had already filed first papers (the declaration of intention), second papers (the petition for naturalization), or the preliminary application for the petition. They also needed state the date on which they filed any of these papers, and the city and state where filed. Question 13 required the individual to indicate if they had any parents, a spouse, and/or children – including the number of children – living in the U.S.⁷ Unfortunately for genealogists, the immigrant did not have to name those living relatives.

Question Groups 14 & 15: Criminal & Foreign Activities

Guadalupe reported that she had no arrests, indictments, or convictions of criminal offenses in the U.S. or any other country. She also stated that in the past five years, she had not been active in or affiliated with any organizations that worked towards supporting “the political activities, public relations, or public policy of a foreign government.”

In question 14, the registrant needed to report if they had ever been arrested, tried, or convicted of criminal office in the U.S. or any other country. If so, they had to “state the nature of the offense, the date of arrest, the city, town or county, the State or country (if outside the United States) where he was arrested, tried, or convicted, and the disposition of the case.”⁷  The individual had to list in question 15 any organizations in which they had been involved the past five years that supported foreign government activities and indicate if they held an official position with any of those groups.⁷

Learning More

In the next post of this blog series, we will discuss where and how you can obtain the WWII-era Alien Registration (AR-2) form for your immigrant ancestors.

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.

Sources

The post What You Can Learn From Your Ancestor’s Alien Registration (AR-2) Form appeared first on Colleen Robledo Greene.

For those of us whose ancestors immigrated to the United States in the 20^th century, your ancestors might have had to register with the federal government as an alien. If so, those records can yield genealogy gold! This is the first post in a new series about researching your immigrant ancestors’ alien registration documents.

Terminology

When I teach about U.S. immigration history, I always start out by clarifying my use of the term alien.  Alien is the legal term for a United States immigrant who has not naturalized and become a U.S. citizen. The term first appears in U.S. immigration-related laws in the Naturalization Act of 1790, the first law to define how a foreign-born immigrant could acquire U.S. citizenship through naturalization.¹ The term immigrant is not specific enough because immigrants can become U.S. citizens, and they still remain immigrants after naturalization.

I personally do not like the term alien. I think it is a dehumanizing word, and it has become a very political and polarizing word. However, alien is a legal term, and we genealogists need to understand the terminology in the laws that applied to our ancestors and in the records that name our ancestors. 

The Alien Registration Act of 1940

The U.S. Congress passed the Alien Registration Act on 28 June 1940 as a national security measure. Although the U.S. did not enter the war until 8 December 1941 – after Japan bombed Pearl Harbor – hostilities in Europe began on 1 September 1939 when Germany invaded Poland. Title I of this act outlawed certain subversive activities, such as advocating for the overthrow of any level of government in the U.S.² Title II amended earlier laws pertaining to the admission and deportation of aliens, such as now denying admission to any alien who is a member of anarchistic organizations.³ Title III is the section of the new law that pertained specifically to alien registration.⁴

Applicable Individuals

The new law required all aliens living in the U.S. for 30 days or longer as of 27 August 1940 to register with the federal government. However, the law exempted foreign government officials and their family members from this requirement. The registration process involved filling out a form, being fingerprinted, and testifying to the accuracy of the information in that form. Aliens age 14 or older had to register for themselves. Parents or legal guardians had to register on behalf of alien children under age 14.

Newly arriving aliens:

• They had to register at the nearest consulate.
• A visa would not be issued without registering.

Aliens who recently arrived:

• Every alien age 14 or older who planned to be in the U.S. for 30 days or longer had to apply for registration before that 30 days expired
• Aliens under age 14 who planned to be in the U.S. for 30 days or longer had to have each of their parents or legal guardians apply for registration for that minor child before the 30 days expired. Upon their fourteenth birthday, each minor alien had to apply for registration for themselves within 30 days of that birthday.

Aliens already living in the U.S. longer term:

• Every alien age 14 or older had to apply for registration by a designated date. This pertained to all non-naturalized aliens even if they had already taken out first or second papers for naturalization.
• Aliens under age 14 had to have their parents or legal guardians apply for registration for that minor child by a designated date. Upon their fourteenth birthday, each minor alien had to apply for registration for themselves within 30 days of that birthday.

The Alien Registration Program

This new federal law led to a three and a half year long program – the Alien Registration Program – to create a national registry of all resident aliens already living in the United States or arriving to the U.S. after the start of this program. The commissioner of the Immigration & Naturalization Service (INS) oversaw the program and registry.

Where, How & When to Register

Each applicable resident alien had to register at their local post office. The law placed responsibility on the postmasters – who could designate their staff – for registering and fingerprinted each applicant. The postmaster then forwarded the registration forms to the Department of Justice in Washington, DC. The INS commissioner could appoint other registration locations and INS employees to process the registrations.⁴ The program was designated to begin 27 August 1940. All applicable resident aliens had to register by 26 December 1940 in the initial registration phase.⁶

Those who chose not to register or filed known false information in their application could be fined up to $1,000 or imprisoned if convicted. The law required registered aliens to notify the INS commissioner of their address every three months and within five days after moving to a new address. Otherwise they could be fined or imprisoned.⁷

How They Knew to Register

Newspapers throughout the U.S. announced the new Alien Registration Act and the registration program, to whom it applied, where and how to register, and the registration dates. These newspaper announcements stressed that registrants would not have to pay any fees. Following is the headline and opening paragraph of an article in the 26 August 1940 issue of the New York Times announcing that national registration would start the next day and go through 2 December 1940.⁸

Foreign language newspapers in the U.S. would have been a critical way in which our immigrant ancestors learned about the new law and registration program, explained in their native language. My Mexican immigrant great-grandmother, her two oldest children born in Mexico, her mother (my 2^nd great-grandmother), and the many members of their immigrant extended family network living in Los Angeles County would have read this 9 August 1940 article in La Opinión [The Opinion], the Spanish-language newspaper founded in Los Angeles. Like the New York Times article, this one stressed that registrants would not have to pay any fees to comply with this new law.⁹

Our immigrant ancestors also likely learned about the new law and required alien registration at their workplaces. The New York Times announcement, which possibly contains boilerplate text sent in a press release by the INS, recommended that employers post noticed at their places of business and allow relevant employees to have time off from work to go register.⁸

The Registration Form

Registrants were required to fill out a designated form, an Alien Registration Form (AR-2 Form). Temporary forms (AR-1 Forms) were available at post offices and resident aliens were encouraged to pick up a temporary form ahead of time to review and fill out at home before showing up for official registration to fill out the permanent AR-2 version of the form in person. If the registrant brought a temporary form to the post office on registration day, a stenographer copied the information from the temporary form to the permanent form while the registration had their fingerprints taken.¹¹

The AR-2 form consisted of 15 sets of questions pertaining to the background and activities of the resident alien. The individual had to swear to the accuracy of the information, be fingerprinted, and then sign their name. When they INS received the AR-2 form, they assigned a unique Alien Registration Number (AR# or A#) to the individual, which followed that individual until naturalization – if they became a US. citizen – or until death. The INS then mailed the registrant an Alien Registration Card to keep as proof of registration.

The document above is the Alien Registration Form (AR-2 Form) for my great-aunt Maria Guadalupe “Lupe” Robledo Nieto, who at this time in 1940 went by Guadalupe Mary as her given name and her married surname of Perez.

We will go over the form more in-depth in the next post of this series and explain where and how to find the Alien Registration Forms for your 20^th century ancestors.

Sources

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I am happy to announce that I have partnered with Legacy Family Tree Webinars again this year to bring you another great series of educational webinars focusing on Mexican and Mexican American genealogy.

The 2026 Webinar Schedule

I have a great teaching team of colleagues joining me to provide excellent in-depth instruction for researching Spanish colonial, Mexican, and Mexican American families. I learn so much from each of these great instructors myself.

Using Marriage Dispensations to Find Ancestors in Mexico

Marriage dispensations provide a privileged window into social and family life in viceroyal Mexico. Dispensations, or special permissions to marry granted by Catholic bishops, reveal the obstacles that had to be resolved before ecclesiastical authorities in order to contract marriage. This webinar examines dispensations for consanguinity and for ultramarinos (foreign-born individuals). In areas with high levels of endogamy, marriage dispensations become essential resources to reconstruct family relationships, even extending beyond other church records.

• Date & Time: Friday, January 16, 2026 (2:00 pm Eastern)
• Instructor: Nefi Arenas Salazar, AG®

The Largest Diocese: History and Records of the Archivo Histórico del Arquidiócesis of Guadalajara

Overview of the history of the Guadalajara archdiocese and its changing boundaries, which impact research throughout many regions of Mexico. We will also review the collections held by the Archdiocese archives and what is available online and in-person. 

• Date & Time: Friday, March 20, 2026 (2:00 pm Eastern)
• Instructor: Lisa Medina

From swords to settlers: Researching conquistador ancestors in 16th century New Spain (Mexico)

Many families in Mexico and beyond descend from the first Spanish conquerors and settlers of New Spain. This webinar will guide you through key sources and strategies to identify conquistador ancestors in the 1500s. Learn how to navigate both Spanish and colonial archives, and to connect names across centuries from books, contemporary chronicles, petitions to the Spanish government, and more. 

• Date & Time: Friday, May 15, 2026 (2:00 pm Eastern)
• Instructor: Nefi Arenas Salazar, AG®

Wills and Testaments in the Spanish Colonial Southwest

This presentation uncovers the genealogical treasures hidden within Spanish colonial wills and testaments. Far more than simple legal documents, these records provide rare insights into family relationships, inheritance patterns, and extended kinship networks that shaped colonial communities. Detailed inventories of clothing, household goods, livestock, and personal possessions offer intimate glimpses into the daily lives of our colonial ancestors — revealing their values, cultural traditions, devotion to faith, and resilience on the far edges of the Spanish frontier. Attendees will also learn where to locate these records, how to analyze their contents, and effective strategies for integrating them into personal research to build richer, more accurate family histories.

• Date & Time: Friday, July 17, 2026 (2:00 pm Eastern)
• Instructor: Henrietta Martinez Christmas

Husband, Father, and Revolutionary: The Case of Ramón Treviño

Listen to the powerful and fascinating story of Mexican revolutionaries as we examine records from both sides of the border to trace the movements (and confirm the identity) of Ramón Treviño, who was surveilled by Mexican and U.S. authorities in the lead-up to the revolution.

• Date & Time: Friday, September 18, 2026 (2:00 pm Eastern)
• Instructor: Lisa Medina

Taking a Deep Dive into Mexico – U.S. Border Crossing Records

The documents found in the U.S. border crossing record collections are packed with valuable information often missed when researching Mexican immigrants. This webinar covers historical legal context pertaining to record keeping at the Mexican border, examines the most common types of documents in these collections, and highlights situations specific to researching Mexican families. Learn how to decipher clues found in these records that lead to other important immigration records and how to obtain those.

• Date & Time: Friday, November 20, 2026 (2:00 pm Eastern)
• Instructor: Colleen Robledo Greene, MLIS, FTxSGS

How to Register for the Series

Registration is open for the Legacy Family Tree Webinar 2026 Mexico Research Series. That web page will allow you to bulk register for the entire series all at once. Register today on the Legacy Family Tree website!

Can’t make the live broadcast times? Recordings will be available in the Webinar Library.

About Legacy Family Tree Webinars

Legacy Family Tree Webinars produces a regular series of high quality educational webinars on a variety of genealogy topics, for all levels of experience. Live webinars are available free to the public. However, a subscription membership provides on-demand access to their robust library of previously recorded webinars and a copy of the presentation handout.

I factor an annual membership ($49.95) into my genealogy education plan and budget.

The post Legacy Family Tree Webinars 2026 Mexico Research Series appeared first on Colleen Robledo Greene.