Alien registration records (AR-2 and A-Files)

Who registered

The 1940 program aimed to register every alien in the country, not only citizens of enemy nations. According to USCIS, more than five million alien residents registered at post offices from August to December 1940 alone. People who were unsure whether they were citizens were also required to register, even if it later turned out they were.

USCIS reports that most registrants were born between 1875 and 1910. USCIS also notes that many 1940 and 1941 registrants had already lived in the country for decades. Children under 14 were not required to register, though some were registered in a separate number series, and USCIS notes that not all children were.

What the AR-2 asks

The form asked for the person's name, the name used when entering the United States, and any other names. It asked for the address, exact date and place of birth, citizenship or nationality, sex, marital status, race, height, weight, and hair and eye color.

For immigration research the most useful questions cover arrival: the port, date, ship, and class of admission at the last arrival, the date of first arrival, the number of years in the United States, and how long the person intended to stay. The form also asked for usual and present occupation, the employer's name and address, memberships in clubs or societies over the past five years, any military service with country, branch and dates, whether the person had filed a declaration of intention or a petition for naturalization, with the date and the city and state, and any arrest record.

Each registrant signed the form and gave a fingerprint. Someone who could not write made a mark, and a friend or witness signed for them. The registration official, usually a postal employee, stamped the date and place of registration.

Treat the arrival answers as leads. USCIS gives the example of a man who came from Mexico to Texas as an infant in 1855: his arrival information came from memory and was not verified, but if he never naturalized, his AR-2 may be the only record where he claimed a port and date of arrival. Family members are not named on the form.

Getting the AR-2

Every AR-2 was stamped with an Alien Registration Number, or A-number. The INS microfilmed 5,665,983 forms in A-number order and indexed them by name, date of birth, and place of birth, with up to three names per person if more than one was given. Most of the original paper forms were later destroyed, though some ended up inside A-Files.

The AR-2 microfilm is held by USCIS, and copies come through its Genealogy Program, a fee-based service. A record request must include the A-number. USCIS suggests looking for it on index cards to court naturalization records after 1941, on the person's alien registration receipt card, or among family papers. If you cannot find the number, an index search request can identify it for someone who registered in 1940.

To tell apart two people with the same name and birth date, USCIS says the most useful details are the person's residence around 1940, down to the town and county, and their occupation.

From AR-2 to A-File

The AR-2 series closed on March 31, 1944. From April 1, 1944, the INS kept an individual file for each alien under their A-number, called an A-File. A-Files were opened for every immigrant who arrived after April 1, 1944, and for anyone who naturalized after April 1, 1956. A-Files numbered below 8 million cover all immigrants admitted from April 1, 1944 to May 1, 1951.

Having an AR-2 does not mean there is an A-File. An older immigrant who registered in 1940 got an A-File only if their case was reopened after April 1, 1944, for example by applying to replace a document, asking for a border crossing card, or petitioning for a relative. The INS could also open a file on its own, such as for an investigation. When an older file was reopened, earlier records like visa files were often moved inside it.

Timing also decides where the papers ended up. Between April 1, 1944 and March 31, 1956, when an alien naturalized, the INS moved all their records into their naturalization certificate file, or C-File, and the A-File ceased to exist. So an immigrant who naturalized before April 1, 1956 will usually have a C-File, not an A-File.

An A-File can be a few pages or hundreds. They may hold visas, photographs, applications, affidavits, and correspondence, depending on how much contact the person had with the agency.

A-Files at the National Archives

In 2009 USCIS and the National Archives agreed to make A-Files permanent records, eligible for transfer to the National Archives 100 years after the immigrant's year of birth. Most are being centralized at the National Archives at Kansas City, while the National Archives at San Francisco keeps some from the San Francisco, Honolulu, Reno and Guam district offices.

As of August 2025, Kansas City held more than 1.5 million A-Files and San Francisco more than 300,000, all for people born in 1925 or earlier, with large gaps. Every name in those holdings can be searched in the National Archives Catalog. If the person is there, you can order copies for a fee or view the file by appointment. If not, the file may still be with USCIS.

Not the same as enemy alien records

During World War II, natives of Germany, Italy and Japan were treated as enemy aliens and came under extra controls, including registration and, for some, internment. Those programs created their own records, held by the National Archives. The AR-2 program was separate and covered aliens of every nationality, so a German-born grandmother may appear in both kinds of records.