Custodial detention / A-B-C list

The Custodial Detention List and the A-B-C classification matrix was used to evaluate the "dangerousness" of organizations and individuals and pre-designate those who would be later interned when the United States went to war against the Axis forces. In total, the United States interned 31,899 nationals of Japan, Germany, and Italy from the contiguous United States, Hawai'i, Alaska, and Latin American countries as part of its Custodian Detention Program. Many Japanese ancestry persons mistakenly referred to these as the "Issei Camps." While those of Japanese ancestry constituted the majority internee population, this internment process should not be confused with the larger incarceration of over 110,000 Japanese nationals and American citizens authorized under Executive Order 9066 .

World War II Internment Program Background

During World War II, United States agencies and the military engaged in interning and incarcerating individuals and groups whom they considered to be suspect or dangerous to the national security. The incarceration program is the most well-known program where the government evicted over 110,000 persons of Japanese ancestry, both immigrants, the Issei , and American citizens, the Nisei and Sansei , from their homes and sequestered them into ten American concentration camps. The authority for this incarceration process was Presidential Executive Order 9066 signed on February 19, 1942. The internment program is a separate and lesser known program whereby 31,899 men, women and children—17,447 of Japanese ancestry, 11,507 of German ancestry, 2,730 of Italian ancestry and 185 others—were so interned starting from December 7, 1941 , and continued until years after 1945. [1] The authority for the internment was the Alien Enemies Act of 1798 [Section 21, Title 50, of the US Code, April 16, 1918], invoked subsequent to a declaration of war along with three Presidential Proclamations [2525 to 2527] declaring nationals from Japan, Germany, and Italy to be alien enemies and ". . . liable to be apprehended, restrained, secured and removed as alien enemies."

By the end of World War II, changes within the internment process resulted in a complex story. A four-part conceptual division assists in understanding this complexity. Part one concerns the precursor events to the Japanese attack on Pearl Harbor, including preparing for and initiating the preliminary investigations of organization and individuals followed by the data evaluation process. The second phase starts with the attack on December 7, 1941, and includes the declaration of war with Japan, Germany, and Italy, and the initiation of the pre-planned arrest and detention process. The third phase concerns the activities surrounding the permanent internment and control of those now designated as alien enemy internees. The fourth and final phase includes the actions after V-E and V-J days with the internees' release, repatriation, or deportation.

This article's focus is on the initial phase, the precursor investigations leading up to the actual arrest and detention phase. Few Americans are aware of how the government designated particular individuals to be arrested and the creation of the process by which the arrests occurred on and after December 7, 1941.

Early Years

An early model for this internment program dates back to World War I. Then, the U.S. initially arrested around 6,400 mostly German immigrant nationals residing in the United States, released 4,000 and interned around 2,400 for some or all of the war years. The authority for this action was the same Alien Enemies Act of 1798. Many nations have in place statutory authority to apprehend nationals of declared enemy nations residing in their countries. From the 1920s into the 1930s, the United States' Department of the Navy's Office of Naval Intelligence (ONI), the War Department's Military Intelligence Division (MID), the Justice Department's Federal Bureau of Investigation (FBI), the State Department, and special envoys of President Franklin D. Roosevelt were involved in various aspects of intelligence and counter-intelligence activities to thwart potential acts of espionage, sabotage, and other fifth-column activities.

Office of Naval Intelligence—Navy Department

The Department of the Navy watched Japan's militarism in the Pacific Ocean from the 1920s and from the 1930s also paid particular attention to the large population of Japanese immigrants, the Issei and Nisei, living in the Territory of Hawaii. President Roosevelt underlined this concern when he proposed to the Chief of Naval Operations on August 10, 1936, ". . . that every Japanese citizen or non-citizen on the Islands of Oahu who meets these Japanese ships [arriving in Hawaii] or has any connection with their officers or men should be secretly but definitely identified and his or her name be placed on a special list of those who would be the first to be placed in a concentration camp in the event of trouble." [2]

Germany and Japan were the nations of concern especially from 1936, with Italy added in 1937, when they signed the Anti-Comintern Pact and engaged in military incursions into their neighboring countries. These three countries, with subordinate allies, became known as the Axis Powers. Concern over intelligence forays from potential enemy nations resulted in the arrests and convictions of espionage activities in the United States from 1938, and by 1945, ninety-one persons were so convicted. Most of those so convicted worked for Germany or Nazi interests and no Issei was ever convicted of committing such acts before or during World War II. [3]

Although the initial investigations and the evaluating assessment of the investigations are distinct and separate activities, from at least 1938 the ONI undertook both functions as they compiled lists of suspect organizations and individuals. [4] That is, after gathering relevant information about a targeted organization, the ONI then assessed its degree of "dangerousness" to the national security interests. In Hawaii, for instance, the ONI watched the Japanese consulate personnel and especially their naval attaches. Their evaluative matrix ranked suspect organizations into three categories: "A" and "B" and "Semi–Official and Subversive Japanese firms in the United States." [5] An "A" designated organization, according to the ONI, was ". . . deemed to constitute an actual threat to the internal security of the United States. All officers and members, whether full or associate, of these organizations should be given serious consideration before employment in any position of confidence or trust in this country. [6] Eighty-eight Japanese organizational names were listed here, with a particular organization counted numerous times with its Japanese name, translated English name, and regional and subsidiary titles counted as a separate entry. The "B" listed organizations posed "potential threats to the national security" [7] One hundred and seventy-six organizational names are listed here, again with its Romanized Japanese name, translated English and regional associations and local chapters recorded as a separate entry. [8] The third category, "Semi-Official and Subversive Japanese firms" were considered of lesser dangerousness and included Japanese steamship companies, banks, newspapers, and a few businesses, each listed separately with accompanying translated English names.

Military Intelligence Division—War Department

At least from October 1938 the War Department's Military Intelligence Division [MID] on the West Coast compiled data on persons of Japanese ancestry and their population centers. As a classified FBI memorandum of that year reported: "Colonel H. R. Oldfield in charge of Military Intelligence for the Ninth Corps area [headquartered in San Francisco] confidentially related to [FBI] Agent J. H. Rice that he was compiling data reflecting the Japanese population and determining those areas where the majority of the Japanese reside in California. The purpose of this information is in case at a future date it might be necessary to establish concentration camps for Japanese in case of emergency." [9]

Federal Bureau of Investigation and the Custodial Detention Program

While the army and navy's concerns centered on protecting the welfare of their military personnel, installations, and bases, the Federal Bureau of Investigation, the main investigative arm of the Department of Justice (DOJ), was concerned with national security matters. Before the 1930s the United States had no national government agency responsible for counterintelligence matters but with increasing military activity on the part of Axis countries from the mid-1930s and onward, counterintelligence issues began to increase in urgency as espionage activities increased against the United States. President Roosevelt directed in September 1939 that the ONI, MID, and the FBI pursue counterespionage and other related internal security matters. The "other related" matters resulted in early coordination between the three agencies such as the FBI leading mutual training activities and the ONI allowing full access of their investigative files to the other two agencies. This latter action was halted in 1940. [10]

In 1939, John Edger Hoover, Director of the Federal Bureau of Investigation, without any statutory authority, started a Custodial Detention list that included German and Italian nationals and citizens of German and Italian ancestry along with those with Communist sympathies" [11] for arrest and internment when the situation dictated this action. No Japanese or Japanese American organizations were initially included or named in the FBI list until late 1941. [12]

Hoover's action in creating a list of persons to be apprehended concerned the DOJ and in April 1941, the Department ordered the FBI to cease its compilation of names and organizations and to turn over the evaluation function to the Neutrality Laws Unit [NLU] formed in 1940. The NLU's purpose, with its name changed to the Special Defense Unit [SDU], was to advise and aid the United States Attorneys charged with the enforcement and prosecution of federal statutes on espionage, sabotage, and violation of the Neutrality Acts. Hoover partially complied with this order by sending 10,000 names and files to the SDU. However, rather than stopping this activity, the FBI continued to maintain its own Custodial Detention list through the war years. [13]

By October 1941, the SDU's priority focused on Nazi and Communist organizations and to a lesser extent, Italian, Japanese, and other Fascistic organizations. [14] The SDU also utilized the A-B-C hierarchical ranking system and followed the ONI's matrix with slight modifications. [15] For instance in the "A" designation, the SDU list divided the organizations into two levels, "A-1" and "A-2." For the A-1 level, the organization was itself classified as "dangerous," an individual's membership alone was sufficient to place his or her name onto the Custodial Detention List, and the information source was deemed reliable. An A-2 level also deemed the organization to be "dangerous" but required that a membership "must be accompanied by actual activities within the organization," and that the information source required additional authentication. [6] A second difference from the ONI list involves the quantity of listed organizations. The SDU listed only twelve Japanese organizational names on the "A" list versus the ONI's eighty-eight names. In essence, however, the listed organizations were predominately identical with the ONI's list counting separately each constituent element of the organization while the SDU listed only its major name in Japanese with an English translation. As with the ONI's list, the SDU's "B" category organizations, also divided into "B-1" and "B-2" subcategories, were considered "less dangerous" but as being "directly" or "indirectly" under the control of the Japanese government with its fundamental purpose to aid Japan in its war effort. The "C" category organizations were those with ties to Japan but were seen as even less "dangerous" than the other two categories.

The "A" category organizations that headed both the ONI and SDU lists were the Kokoryukai [Black Dragon Society] and Sokokukai [Fatherland Society]. The former organization was seen as training and abetting persons to conduct espionage and sabotage activities against an adversarial nation. There is some doubt about the Kokoryukai's actual existence in the United States and within the Issei community. [16] Sokokukai was the title of a Japanese nationalist magazine for which an Issei's name on a subscription roster alone sufficed for some to be arrested and interned. [17] The SDU's "B" category listed nine organizations, such as the Nihonjinkai [Japanese Association], Shinto Temples, and the Nichibei Kogyo Kaisha in Los Angeles [The Great Fujii Theater Company]. [18] The "C" listed organizations consisted of Japanese businesses or cultural organizations such as judo clubs and Japanese flower arranging societies. [19]

Besides the leaders and others with active participation in these listed organizations the FBI investigators were assisted by informers, malcontents, and anonymous finger-pointers both outside and inside the Japanese American communities. [20] The FBI here arrested non-organizationally listed affiliated individuals such as the publishers and editors of vernacular Japanese language newspapers, principals of Japanese language schools, and others.

The Special War Problems Division—State Department

On September 1, 1939, the State Department through their Special War Problems Division [SWPD] collected intelligence materials on diplomats and other nationals from Germany, Italy, and Japan with discussion ensuing within the State Department on the treatment of diplomatic persons in the event of war. On December 7, 1941, FBI agents placed all Japanese embassy and various consulate officials under house arrest until the diplomats and their families could be transported to temporary internment centers. Here, they were kept in luxurious resorts in Virginia, North Carolina, and West Virginia until they could be exchanged for Allied diplomatic persons trapped in Axis countries. In addition to Japanese diplomatic personnel the State Department brought business and corporate executives and some internees from the DOJ internment camps for the later exchanges. Within the United States, the State Department temporarily interned 785 diplomatic and other persons – 363 Japanese, 212 Germans, 113 Italians, 71 Hungarians, 16 Bulgarians and 10 Romanians. From Latin American countries, the United States transported and accepted 1,735 diplomatic or other officials – 1,194 Germans, 493 Japanese and 48 others. Although most were repatriated by September, 1942, the last State Department temporary internment center was open until February 15, 1944. [21]

Custodial Detention Program

On December 7, 1941, during the attack on Pearl Harbor, the army wired "the four commanding generals and the nine corps commanders to work with the FBI to 'round up' all persons on their detention list." [22] And within hours of the attack, the FBI sent telegrams to their field offices: "Urgent. Immediately take into custody all Japanese who have been classified in the A,B, and C categories in materials previously transmitted to you. . . [signed] Hoover." [23] Using this telegram as authorization, FBI agents began arresting all persons of Japanese ancestry on the lists, regardless of their custodial detention status. The FBI, by the end of the day, arrested 736 mainland Issei and some German and Italian aliens.

There is some question concerning the extent to which the FBI field offices supplemented the names from the SDU Custodial Detention List with names their own FBI generated List. What is known is that arrests were made by various U.S. agencies on the Issei and some Nisei just after December 8, 1941, and then requests were made for Presidential Warrants to justify holding these individuals. These arrests were effected without offering a reason, justification, or warrant for their actions.

Within the Japanese and Japanese American communities, the arrests, detention, and incarceration of these Issei men and some women created extreme personal and familial hardships. They had committed no crimes, there were no charges brought against them, they had no access to legal counsel, and their basic loyalty to Japan was not surprising as the Issei were, by law since 1922, aliens ineligible for naturalization. However, having personal loyalties to another country, as did many Japanese, German, and Italian immigrants, is not the same as harboring disloyal sentiments against the United States. And their arrests were a product of guilt by association with a "suspect" organization.

Even within the government, and especially in the Department of Justice, questions were raised about the efficacy of the methods used in the Custodial Detention Program to determine the classification levels. In July 1943 after the DOJ conducted an internal review of the classification system, Attorney General Francis Biddle found it to be without merit, that the "dangerousness" designation of organizations was based on "unreliable hearsay and other varieties of dubious information. . . [and the evaluative system] "attempted to determine danger in vacuo" without defining the elements or nature of the danger. [24] Biddle recommended that for American citizens placed on the Custodial Detention List that their classification be expunged. [25] Although most of the Japanese ancestry internees were Issei men, women, and a few Nisei originating in the contiguous United States, the Territory of Hawaii, and Alaska, other men with their families later were interned after being virtually kidnapped and brought to the United States from Latin American countries.


The Custodial Detention Program with the Custodial Detention List and the A-B-C classification matrix for organizations and individuals constitutes the beginning of the internment. Although the investigative activities continued through the war years, the second or detention phase started from the initial arrests on December 7, 1941, to 1943. The third phase, the internment procedure itself and the last segment of the internment saga includes the years from 1942 to 1947, or two years after the end of hostilities, and ends with the internees' release, repatriation, or deportation from the United States.

Authored by Tetsuden Kashima , University of Washington

For More Information

Fukuda, Yoshiaki. My Six Years of Internment: An Issei's Struggle for Justice' . San Francisco: Konko Church of San Francisco, 1990.

Kashima, Tetsuden. Judgment Without Trial: Japanese American Imprisonment during World War II . Seattle: University of Washington Press, 2004.

Soga, Yasutaro. Life behind Barbed Wire: The World War II Internment Memoirs of a Hawai'i Issei . Honolulu: University of Hawai'i Press, 2008.

Tana, Daisho. Santa Fe, Rozubagu, senji tekikokujin yokuryujo nikki, dai-ikkan . (Santa Fe, Lordsburg, wartime enemy internment place diary, vol. 1). Tokyo: Sankibo Busshorin Seisaku, 1976.


  1. Bishop Yoshiaki Fukuda was arrested on December 7, 1941 and released on September 29, 1947, from the DOJ Internment Center at Crystal City, Texas, See Yoshiaki Fukuda, My Six Years of Internment (San Francisco: Konko Church of San Francisco, 1990), 135.
  2. Quoted in Okihiro, Gary Y., Cane Fires (Philadelphia: Temple University Press, 1991), 173.
  3. Tetsuden Kashima, Judgment Without Trial (Seattle: University of Washington Press, paper, 2004), 20.
  4. Kashima, Judgment , 36–37.
  5. Kashima, Judgment , 37–38.
  6. 6.0 6.1 Kashima, Judgment , 231, footnote 91; quote from U.S. Army Report, U.S. Army Records of the Adjutant General's Office, Record Group [RG] 497, Appendix II, Tab 1, 1947, p. 130, National Archives [NA], [Washington D.C.]. Cite error: Invalid <ref> tag; name "ftnt_ref6" defined multiple times with different content
  7. Kashima, Judgment , 231.
  8. Kashima, Judgment , 231, footnote 92.
  9. Quoted in Kashima, Judgment , 35.
  10. A History of the Office of Naval Intelligence, 1882-1942, Neutrality and Espionage ; FBI memorandum, file 100-2-5-00, December 12, 1941, National Archives, Washington D.C.
  11. Curt Gentry, J. Edgar Hoover: the Man and the Secrets (New York: Penguin Books, 1991), 213.
  12. Kashima, Judgment' ', 29.
  13. Kashima, Judgment , 28.
  14. Kashima, Judgment , 28.
  15. Kashima, Judgment , 30.
  16. See Kashima, Judgment , 30 and 229, footnote 72.
  17. Kashima, Judgment , 31.
  18. Kashima, Judgment , 32.
  19. Kashima, Judgment , 32.
  20. Kashima, Judgment , 23, 46 and passim.
  21. Kashima, Judgment , 180–182.
  22. Radiogram, Adjutant General to Army and Corps Commanders, 7 December 1941, U.S. Army, Records of the Adjutant General's Office, RG 407, Provost Marshal General, File Number PMG 014.311-81, N.A. Classified "Secret" (Declassified).
  23. Telegram, 7 December 1941, FBI File Number 100-2-20-23, N.A., Washington D.C.
  24. Memorandum, DOJ, July 13, 1943, RG 85, File Number 62-63892-4, p. 2-g, N.A., Washington D.C.
  25. Memorandum, DOJ, July 13, 1943.

Last updated Dec. 18, 2023, 7:40 p.m..