Terminology and the Mass Incarceration of Japanese Americans during World War II

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It is important to accurately describe the history of the mass incarceration of Japanese Americans during World War II without perpetuating euphemistic terms that the US government and others employed at the time, or incorrect terms later substituted that do not adequately describe the injustice experienced by more than 120,000 people.

The National Park Service (NPS) units preserving the Japanese American confinement sites should provide safe places for people to experience, learn about, and in some cases remember the historic events that occurred there. It is our responsibility to base our historical interpretation on a variety of reliable sources while taking into consideration the diverse viewpoints of visitors. Using accurate language can be one way of adding depth to the government’s approach to and level of understanding of Japanese American removal and confinement. Therefore, it is important that we strive for historical and academic accuracy in choosing our words, and that we educate visitors about the context, both past and present, in which particular words were used.

The NPS has not published standard guidance on terminology related to Japanese American World War II experiences. NPS employees regularly engage with people who experienced removal and incarceration based on their ethnicity, as well as the general public. NPS employees are often mobile and may transfer to work at Japanese American confinement sites with limited or no background related to Japanese American removal and incarceration. These factors make a reference such as this paper an essential resource for the NPS.

This paper attempts to define and contextualize some of the prevalent terms and offers guidance about usage.


On February 19, 1942, following Japan’s December 7, 1941 bombing of Hawai‘i as well as decades of discriminatory laws directed against Japanese immigrants and their children, President Franklin D. Roosevelt issued Executive Order 9066. The order directed the US Secretary of War to “prescribe military areas . . . from which any or all persons may be excluded.” Acting under that authority, General John DeWitt orchestrated the forcible removal of more than 110,000 Japanese Americans­—including those who were US citizens by birth and their Japanese immigrant parents—from their West Coast homes and communities.[1] They were rounded up, transported, and incarcerated in remote areas under harsh and overcrowded conditions in facilities run by the War Relocation Authority (WRA). By war’s end, the United States had incarcerated 120,000 Japanese Americans in government camps and facilities.[2]

Throughout World War II, the US government used newsreels and press coverage to portray the forced mass removal, confinement, and dispersal in a benign light. Spokespeople used carefully chosen words and images to communicate these processes, the places where people were being confined, and the people themselves. “Evacuation” and “relocation” and their derivatives, such as “evacuee” and “relocation center,” were the most prevalent words. The government also launched a subsequent massive campaign promoting a different kind of “relocation,” urging people who had been forcibly incarcerated to leave the confinement camps and resettle outside of the western states.


There is not universal consensus concerning terms used to describe the history of Japanese American incarceration during World War II. Highly charged debates over words and terminology continue to reflect intense feelings and diverse perspectives about what occurred during World War II and what those events mean today.

Many different words have been and continue to be used to describe the US government’s wartime policies toward Japanese Americans. Words used to describe the forced removal of people from their homes and communities and their subsequent incarceration include detention, confinement, evacuation, exclusion, imprisonment, incarceration, internment, and relocation. The people themselves have been referred to as evacuees, detainees, incarcerees, inmates, internees, non-aliens, and prisoners. The people have also been described as Japanese, Japanese Americans, Japanese resident aliens, Nikkei (people of Japanese ancestry), and by their generation in the United States—Issei (first generation), Nisei (second generation), Kibei (Nisei sent to Japan for education and returned to America), and Sansei (third generation).[3] Finally, the facilities used to implement the government’s policies have been called assembly centers, camps, concentration camps, detention facilities, incarceration centers, internment camps, prisons, and war relocation centers.

Discussions about terminology have occurred for decades, beginning during World War II and gaining attention during the Redress Movement in the 1960s and 1970s – and long before formal NPS involvement.[4] Scholars and stakeholders including Roger Daniels, Sue Kunitomi Embrey, Aiko Herzig-Yoshinaga, Yoshinori H. T. Himel, James Hirabayashi, and Raymond Okamura have addressed terminology in published essays. The Japanese American Citizens League, as well as the non-profit organization Densho, also have published guidance on terminology.

Specific terms have been debated and vetted, while some continue to be highly controversial. In particular, the term “concentration camp” has spurred discussions with survivors and descendants of Nazi Germany’s Holocaust. In 1998, the American Jewish Committee and Japanese American National Museum held a large and formal discussion at Ellis Island about the use of “concentration camp” to describe the World War II incarceration of Japanese Americans. Although that discussion resulted in a joint statement, beginning in 2018, the American Holocaust Memorial Museum published statements seemingly in opposition.

In 2020, terminology continues to be one of the most relevant and often-discussed topics associated with the history of Japanese American incarceration.

Going Forward

Words that a person uses reflect what they have experienced, their depth of knowledge, and their worldviews. The selection of particular words by an individual or by consensus within an organization may also serve ideological or political purposes. In addition, the use of specific words and our understanding of them changes over time, and this is precisely the case that the NPS and public are grappling with at this time. It is for this reason that the NPS has taken an interpretive approach to addressing terminology, one in which the topic is used as an educational tool in appropriate contexts.

The words we choose for interpretation and education have a profound influence on what the United States and international public understand about the incarceration experiences of Japanese Americans during World War II. We need to ensure that we are transparent and open about terminology.

NPS staff recognize and respect that those who were incarcerated may use whatever words they choose to describe their experiences. As representatives of the NPS, interpreters and other staff members strive to use accurate words that do not promote misinformation but rather allow all visitors the opportunity to learn.

We will continue to have open discussions with people about the power of words.

The following glossary is divided into terms used to describe the facilities where people were held, the movement of people, and the people themselves. It includes terms that the US government used during World War II and suggests more accurate alternatives.


Facilities and Types of Confinement

Assembly Center:

The US government used the term “assembly center” to refer to the racetracks, fairgrounds, and other existing facilities, as well as the newly built Manzanar facility, run by the US Army’s Wartime Civilian Control Agency for part of 1942 where Japanese Americans were confined under armed guard while awaiting more permanent facilities. Use it only when necessary in a historical context as part of a proper name, such as Tanforan Assembly Center. In most cases, one can use the site’s actual name before the US Army appropriated it, such as Tanforan Racetrack.

Other suggested terms include detention center, confinement site, incarceration center.

Concentration Camp:

Scholars and stakeholders who have examined use of the term concentration camp to describe Japanese American incarceration sites broadly agree that the term is an accurate one. In 1998, the Japanese American National Museum and American Jewish Committee issued a joint statement in advance of an exhibit at Ellis Island addressing the usage of “concentration camp.”

The joint statement defined a concentration camp as “a place where people are imprisoned not because of any crimes they have committed, but simply because of who they are.” After giving a short description of various historical concentration camps, the authors concluded: “Despite differences, all had one thing in common: the people in power removed a minority group from the general population and the rest of society let it happen.”[5]

NPS staff are encouraged to understand the multiple contexts in which the term concentration camp has been used and its deeply affecting nature. The term may be included, with context, in exhibits or publications. NPS staff are encouraged to allow people who experienced Japanese American removal and confinement and other members of the public their own perspectives on the appropriateness of the term concentration camp in the Japanese American context.

Imprisonment vs. Incarceration:

Although these terms are quite close in meaning, there is a critical difference: A person is imprisoned due to being convicted of, or pleading guilty to, a crime, whereas a person is incarcerated for a variety of reasons. “Incarceration” does not include a value judgment of a person’s wrongdoing – it refers to someone being confined somewhere. The key to this difference is demonstrated in the term “false imprisonment” for an innocent person being incarcerated in a prison.[6] To incarcerate someone does not suggest that the person has been found guilty of a crime, as imprisonment does. It is not a heated term and is not inaccurate. The 10 facilities run by the War Relocation Authority can be referred to accurately as incarceration or confinement sites.

Internment Camp, Internment:

During World War II, the Department of Justice and US Army detained and interned targeted non-US citizens who were resident aliens from Japan, Germany, Italy, and a few other nations. As citizens of countries with which the United States was at war, those people generally were treated according to the Geneva Conventions requiring humane treatment to prisoners of war. Maps that show sites of Japanese American confinement during WWII differentiate between those Department of Justice or US Army internment camps and the 10 War Relocation Authority confinement sites that held US citizens of Japanese ancestry.

The internment of residents who were not US citizens was in alignment with the Geneva Conventions of 1864, 1906, and 1929. For an excellent explanation of this, see “Americans’ Misuse of ‘Internment’,” by Yoshinori H. T. Himel. He states in the introduction:

Many Americans have used the word “internment” to denote World War II’s civil liberties calamity of mass, race-based, nonselective forced removal and incarceration of well over 110,000 Japanese American civilians, most of them American citizens. But the word “internment,” a term of art in the international law of war, does not describe that community-wide incarceration. Instead, it invokes an internationally agreed legal scheme under which a warring country may incarcerate enemy soldiers and selected civilian subjects of an enemy power.[7]

Although many people use the word “internment” when speaking about the US citizens and their immigrant parents confined in WRA camps, NPS’s educational mission would be advanced by distinguishing between internment camps and other types of confinement sites in NPS exhibits and conversations.

Isolation Center:

This refers to sites at Moab, Utah; Tulelake, California; and Leupp, Arizona; where WRA officials sent some Japanese Americans and their immigrant parents when they wanted them removed from the WRA centers. In particular, people from Manzanar War Relocation Center were sent there in late December 1942. Because many of the people were US citizens and had not been charged with a crime, they did not fall under the jurisdiction of the Army or Department of Justice. The Moab site and Tule Lake Citizen Isolation Center (also known as Camp Tulelake) were former Civilian Conservation Corps (CCC) camps; Leupp, on the Navajo Nation, had been a boarding school.


Not accurate, although sometimes it is used. (See Imprisonment vs. Incarceration above)

Reception Center:

In spring 1942, the facility that would become Manzanar War Relocation Center was referred to as Owen’s Valley Reception Center. It is a term that is rarely used but does appear in historical photos and documents.

Relocation Center:

The US government used the term relocation center to refer to the more permanent facilities run by the War Relocation Authority where Japanese Americans were confined from 1942 until as late as 1946. That term did not convey the overcrowded, harsh conditions, lack of privacy, and loss of family ties that became the reality. Use it only when necessary in a historical context as part of a proper name, such as Manzanar War Relocation Center.

Suggested terms to use when referring to any of the 10 WRA sites: confinement centers, incarceration sites, sites of confinement.

Movement of People


During World War II, the US Army used the term “evacuation” to describe the forced removal of Japanese Americans from their homes in California or parts of Washington, Oregon, Alaska, and Arizona. Although in twenty-first century connotation, different US agencies “evacuate” people to get them out of harm’s way, a review of historic letters, memorandums, orders, and conversations reveals that General John DeWitt, Colonel Karl Bendetsen, and others used the term “evacuation” to describe logistics.

Regardless of WWII-era motivations or connotations, because of today’s association of “evacuation” with avoiding the threat of harm, NPS should not refer to the forced removal of more than 110,000 people from their homes because of their ethnicity as “evacuation.”

Suggested terms to describe the movement of Japanese Americans during WWII include “forced removal,” “expulsion,” and “mass removal.”


During World War II, government officials used “relocation” for two different mass movements of people. First, they used relocation to describe the forced removal of Japanese Americans to War Department assembly centers and War Relocation Authority facilities. Second, beginning in early 1943, the WRA pushed those same people to leave the government facilities and “relocate” to midwestern and eastern states.

As with “evacuation,” today we should avoid referring to the forced removal of more than 110,000 people as “relocation,” or of the WRA facilities as “relocation centers,” despite the use of the word relocation in the agency’s name.
Suggested terms to describe the movement of Japanese Americans during WWII include “forced removal,” “expulsion,” and “mass removal.”


For clarity, one can describe the movement of Japanese Americans out of the WRA facilities to other parts of the United States as “resettlement.”

When Referring to People

Terms such as “evacuee,” “internee,” and “incarceree” derive from peoples’ particular experiences of “evacuation,” “internment,” or “incarceration.” When referring to people, try to respect their humanity by avoiding such labels. Rather than “former incarcerees,” consider saying, “formerly incarcerated people.”

However, since the following terms are in common usage, here are the definitions:


During World War II, government employees referred to the Japanese Americans who were confined in the WRA camps as “evacuees.” Often the people confined also referred to themselves as evacuees.

Do not refer to people who were forced from their homes and put into WRA camps as “evacuees” or even “formerly evacuated people.” The twenty-first century connotation of “evacuation” as moving people out of harm’s way does not convey the harsh, unjust reality that the Japanese Americans endured.

Suggested terms include “people who were forcibly removed from their homes” or “unjustly removed.”


A person, regardless of citizenship status, confined in one of the 10 War Relocation Authority facilities. Nearly all these people were either Japanese immigrants or Americans of Japanese ancestry. There were some non-Japanese American spouses and one teenage boy of Mexican and Irish ancestry also held in those facilities.

Rather than “incarcerees,” say “formerly incarcerated people.”


A non-US citizen confined in a Department of Justice or US Army facility (known as an internment camp) during war against the person’s country. During World War II, the US government interned thousands of resident aliens from Japan, Germany, and Italy. The term remains accurate for those who were not US citizens and were placed in internment camps. However, it would be better to acknowledge the person’s humanity, as noted above.

Rather than “internee” say a “formerly interned person,” or say the person’s name and say he or she had been interned by the US government.


Bartov, Omer, Doris Bergen, Andrea Orzoff, Timothy Snyder, and Anika Walke, et al. “An Open Letter to the Director of the US Holocaust Memorial Museum.” The New York Review of Books, July 1, 2019.
Civil Liberties Public Education Fund. “CLPEF Background.” Accessed September 16, 2019.
Commission on Wartime Relocation and Internment of Civilians. Personal Justice Denied. University of Washington Press, 1997.
Daniels, Roger. American Concentration Camps: A Documentary History of the Relocation and Incarceration of Japanese Americans, 1942–1945, nine volumes. Garland Publishing, New York and London, 1989.
____________. Prisoners Without Trial. New York: Hill and Wang, 1993.
____________. “Words Do Matter: A Note on Inappropriate Terminology and the Incarceration of the Japanese Americans.” Discover Nikkei, February 1, 2008.
Densho. “Terminology.” Accessed September 15, 2019.
Friedberg, Edna. “Why Holocaust Analogies are Dangerous.” United States Holocaust Memorial Museum. December 12, 2018.
Grisham, Lori, and Edward Schumacher-Matos. “Euphemisms, Concentration Camps and The Japanese Internment.” NPR, February 10, 2012.
Herzig-Yoshinaga, Aiko. “Words Can Lie or Clarify: Terminology of the World War II Incarceration of Japanese Americans.” Discover Nikkei, February 2, 2010.
Himel, Yoshinori H.T. “Americans’ Misuse of ‘Internment’.” Seattle Journal for Social Justice Vol. 14, Issue 3 (Spring 2016): 797-837.
Hirabayashi, James A. “‘Concentration Camp’ or ‘Relocation Center’ - What’s in a Name?” Discover Nikkei: Enduring Communities, April 24, 2008.
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Knox, Liam. “Scholars Push Back on Holocaust Museum’s Rejection of Historical Analogy.” The Chronicle of Higher Education, July 3, 2019.
Kunitomi Embrey, Sue. “Concentration Camps, Not Relocation Centers.” Manzanar Committee, 1976.
National JACL Power of Words II Committee. “Power of Words Handbook: A Guide to Language about Japanese Americans in World War II.” Japanese American Citizens League, 2013. Accessed September 15, 2019.
Robinson, Greg. A Tragedy of Democracy: Japanese Confinement in North America. New York: Columbia University Press, 2009.
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[1] The full text of Executive Order 9066 can be found at

[2] These numbers do not take into account non-US citizens interned by the Department of Justice or the US Army in camps, such as Honouliuli in Hawai‘i. See glossary for internment.

[3] The term “Jap” and “Jap Camp” also were used during World War II and in its aftermath. Then and now, these terms are racial slurs that are considered derogatory and hurtful.

[4] The Redress Movement was an effort, largely occurring in the 1960s, 70s, and 80s, to obtain restitution of civil rights, an apology, and monetary compensation by the US government. Grassroots efforts prompted Congress and President Jimmy Carter to establish the Commission on Wartime Relocation and Internment of Civilians. The Commission’s 1983 report concluded that President Franklin D. Roosevelt and General John DeWitt had known that there was no military necessity for the mass incarceration. It attributed the cause to “race prejudice, war hysteria, and a failure of political leadership.” Commission on Wartime Relocation and Internment of Civilians, Personal Justice Denied: The Report of the Commission on the Wartime Relocation and Internment of Civilians (Seattle: University of Washington Press and Washington D.C.: Civil Liberties Public Education Fund, 1997) 459.

[5] Japanese American National Museum, “American Jewish Committee, Japanese American National Museum Issue Joint Statement About Ellis Island Exhibit Set To Open April 3,” March 13, 1998.

[6] See, for example, Webster’s 1828, Cambridge, Collins, and Merriam-Webster dictionaries.

[7] Yoshinori H. T. Himel, “Americans’ Misuse of ‘Internment’,” Seattle Journal for Social Justice, Vol. 14, Issue 3, Spring 2016, pp. 797 – 837.

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Last updated: November 30, 2023