During World War II, about 120,000 people of Japanese descent were forcibly relocated and incarcerated in 10 concentration camps in the United States, operated by the War Relocation Authority (WRA), mostly in the western interior of the country. About two-thirds were U.S. citizens. These actions were initiated by Executive Order 9066, issued by President Franklin D. Roosevelt on February 19, 1942, following Imperial Japan's attack on Pearl Harbor on December 7, 1941. About 127,000 Japanese Americans then lived in the continental U.S., of which about 112,000 lived on the West Coast. About 80,000 were Nisei ('second generation'; American-born Japanese with U.S. citizenship) and Sansei ('third generation', the children of Nisei). The rest were Issei ('first generation') immigrants born in Japan, who were ineligible for citizenship. In Hawaii, where more than 150,000 Japanese Americans comprised more than one-third of the territory's population, only 1,200 to 1,800 were incarcerated.
Internment was intended to mitigate a security risk which Japanese Americans were believed to pose. Military authorities justified exclusion by claiming that an "unascertained number" of potentially disloyal Japanese Americans remained on the West Coast and that immediate separation between loyal and disloyal was impracticable. Military necessity was interpreted broadly to include not only direct defense concerns, but also civilian morale and broader wartime considerations. The implementation of internment developed in stages, progressing from asset restriction measures to large-scale removal and incarceration. The scale of the incarceration in proportion to the size of the Japanese American population far surpassed similar measures undertaken against German and Italian Americans who numbered in the millions and of whom some thousands were interned, most of these non-citizens. Following the executive order, the entire West Coast was designated as a military exclusion area, and all Japanese Americans who were living there were taken to assembly centers before they were sent to concentration camps in California, Arizona, Wyoming, Colorado, Utah, Idaho, and Arkansas. Similar actions were taken against individuals of Japanese descent in Canada. The internees were prohibited from taking more than they could carry into the camps, and many of them were forced to sell either some or all of their property, including their homes and their businesses. Inside the camps, which were surrounded by barbed wire fences and were patrolled by armed guards, the internees frequently lived in overcrowded barracks which contained minimal furnishings.
In its 1944 decision Korematsu v. United States, the U.S. Supreme Court upheld the constitutionality of the removals under the Due Process Clause of the Fifth Amendment to the United States Constitution. Although the Court upheld exclusion under wartime necessity, the decision acknowledged that ancestry based distinctions would ordinarily conflict with constitutional equality principles. The Court limited its decision to the validity of the exclusion orders, avoiding the issue of the incarceration of U.S. citizens without due process, but ruled on the same day in Ex parte Endo that a loyal citizen could not be detained, which began their release. On December 17, 1944, the exclusion orders were rescinded, and nine of the ten camps were shut down by the end of 1945. Japanese Americans were initially barred from U.S. military service, but by 1943, they were allowed to join, with 20,000 serving during the war. Over 4,000 students were allowed to leave the camps to attend college. Hospitals in the camps recorded 5,981 births and 1,862 deaths during incarceration.
In the 1970s, under mounting pressure from the Japanese American Citizens League (JACL) and redress organizations, President Jimmy Carter appointed the Commission on Wartime Relocation and Internment of Civilians (CWRIC) to investigate whether the internment had been justified. In 1983, the commission's report, Personal Justice Denied, found little evidence of Japanese disloyalty and concluded that internment had been the product of racism. Subsequent scholarship also found that government officials had withheld information that undermined claims that Japanese Americans posed a significant security threat. It recommended that the government pay reparations to the detainees. In 1988, President Ronald Reagan signed the Civil Liberties Act of 1988, which officially apologized and authorized a payment of $20,000 (equivalent to $54,000 in 2025) to each former detainee who was still alive when the act was passed. The legislation admitted that the government's actions were based on "race prejudice, war hysteria, and a failure of political leadership." By 1992, the U.S. government eventually disbursed more than $1.6 billion (equivalent to $4.36 billion in 2025) in reparations to 82,219 Japanese Americans who had been incarcerated.
During World War II, about 120,000 people of Japanese descent were forcibly relocated and incarcerated in 10 concentration camps in the United States, operated by the War Relocation Authority (WRA), mostly in the western interior of the country. About two-thirds were U.S. citizens. These actions were initiated by Executive Order 9066, issued by President Franklin D. Roosevelt on February 19, 1942, following Imperial Japan's attack on Pearl Harbor on December 7, 1941. About 127,000 Japanese Americans then lived in the continental U.S., of which about 112,000 lived on the West Coast. About 80,000 were Nisei ('second generation'; American-born Japanese with U.S. citizenship) and Sansei ('third generation', the children of Nisei). The rest were Issei ('first generation') immigrants born in Japan, who were ineligible for citizenship. In Hawaii, where more than 150,000 Japanese Americans comprised more than one-third of the territory's population, only 1,200 to 1,800 were incarcerated.
Internment was intended to mitigate a security risk which Japanese Americans were believed to pose. Military authorities justified exclusion by claiming that an "unascertained number" of potentially disloyal Japanese Americans remained on the West Coast and that immediate separation between loyal and disloyal was impracticable. Military necessity was interpreted broadly to include not only direct defense concerns, but also civilian morale and broader wartime considerations. The implementation of internment developed in stages, progressing from asset restriction measures to large-scale removal and incarceration. The scale of the incarceration in proportion to the size of the Japanese American population far surpassed similar measures undertaken against German and Italian Americans who numbered in the millions and of whom some thousands were interned, most of these non-citizens. Following the executive order, the entire West Coast was designated as a military exclusion area, and all Japanese Americans who were living there were taken to assembly centers before they were sent to concentration camps in California, Arizona, Wyoming, Colorado, Utah, Idaho, and Arkansas. Similar actions were taken against individuals of Japanese descent in Canada. The internees were prohibited from taking more than they could carry into the camps, and many of them were forced to sell either some or all of their property, including their homes and their businesses. Inside the camps, which were surrounded by barbed wire fences and were patrolled by armed guards, the internees frequently lived in overcrowded barracks which contained minimal furnishings.
In its 1944 decision Korematsu v. United States, the U.S. Supreme Court upheld the constitutionality of the removals under the Due Process Clause of the Fifth Amendment to the United States Constitution. Although the Court upheld exclusion under wartime necessity, the decision acknowledged that ancestry based distinctions would ordinarily conflict with constitutional equality principles. The Court limited its decision to the validity of the exclusion orders, avoiding the issue of the incarceration of U.S. citizens without due process, but ruled on the same day in Ex parte Endo that a loyal citizen could not be detained, which began their release. On December 17, 1944, the exclusion orders were rescinded, and nine of the ten camps were shut down by the end of 1945. Japanese Americans were initially barred from U.S. military service, but by 1943, they were allowed to join, with 20,000 serving during the war. Over 4,000 students were allowed to leave the camps to attend college. Hospitals in the camps recorded 5,981 births and 1,862 deaths during incarceration.
In the 1970s, under mounting pressure from the Japanese American Citizens League (JACL) and redress organizations, President Jimmy Carter appointed the Commission on Wartime Relocation and Internment of Civilians (CWRIC) to investigate whether the internment had been justified. In 1983, the commission's report, Personal Justice Denied, found little evidence of Japanese disloyalty and concluded that internment had been the product of racism. Subsequent scholarship also found that government officials had withheld information that undermined claims that Japanese Americans posed a significant security threat. It recommended that the government pay reparations to the detainees. In 1988, President Ronald Reagan signed the Civil Liberties Act of 1988, which officially apologized and authorized a payment of $20,000 (equivalent to $54,000 in 2025) to each former detainee who was still alive when the act was passed. The legislation admitted that the government's actions were based on "race prejudice, war hysteria, and a failure of political leadership." By 1992, the U.S. government eventually disbursed more than $1.6 billion (equivalent to $4.36 billion in 2025) in reparations to 82,219 Japanese Americans who had been incarcerated.
Background
Prior use of internment camps in the United States
The United States government had previously employed civilian internment policies in a variety of circumstances. During the 1830s, civilians who were members of the indigenous Cherokee nation were evicted from their homes and detained in "emigration depots" in Alabama and Tennessee prior to their deportation to Oklahoma following the passage of the Indian Removal Act in 1830. Similar internment policies were carried out by U.S. territorial authorities against the Dakota and Navajo peoples during the American Indian Wars in the 1860s. In 1901, during the Philippine–American War, General J. Franklin Bell ordered the detainment of Filipino civilians in the provinces of Batangas and Laguna into U.S. Army-run concentration camps in order to prevent them from collaborating with Filipino General Miguel Malvar's guerrillas; over 11,000 people died in the camps from malnutrition and disease.
After the United States entered World War I in 1917, roughly 6,300 German-born residents of the United States were arrested, with 2,048 of those residents being incarcerated on two U.S. Army bases, where they remained interned until 1920. However, these policies did not apply to German-American U.S. citizens because they only targeted a small fraction of German-born Americans.
Japanese Americans before World War II
Due in large part to socio-political changes which stemmed from the Meiji Restoration—and a recession which was caused by the abrupt opening of Japan's economy to the world economy—people emigrated from the Empire of Japan after 1868 in search of employment. From 1869 to 1924, approximately 200,000 Japanese immigrated to the islands of Hawaii, mostly laborers expecting to work on the islands' sugar plantations. Some 180,000 went to the U.S. mainland, with the majority of them settling on the West Coast and establishing farms or small businesses. Most arrived before 1908, when the Gentlemen's Agreement between Japan and the United States banned the immigration of unskilled laborers. A loophole allowed the wives of men who were already living in the US to join their husbands. The practice of women marrying by proxy and immigrating to the U.S. resulted in a large increase in the number of "picture brides."
As the Japanese American population continued to grow, European Americans who lived on the West Coast resisted the arrival of this ethnic group, fearing competition, and making the exaggerated claim that hordes of Asians would take over white-owned farmland and businesses. Groups such as the Asiatic Exclusion League, the California Joint Immigration Committee, and the Native Sons of the Golden West organized in response to the rise of this "Yellow Peril." They successfully lobbied to restrict the property and citizenship rights of Japanese immigrants, just as similar groups had previously organized against Chinese immigrants. Beginning in the late 19th century, several laws and treaties which attempted to slow immigration from Japan were introduced. The Immigration Act of 1924, which followed the example of the 1882 Chinese Exclusion Act, effectively banned all immigration from Japan and other "undesirable" Asian countries.
The 1924 ban on immigration produced unusually well-defined generational groups within the Japanese American community. The Issei were exclusively those Japanese who had immigrated before 1924; some of them desired to return to their homeland. Because no more immigrants were permitted, all Japanese Americans who were born after 1924 were born in the U.S. and by law, they were automatically considered U.S. citizens. The members of this Nisei generation constituted a cohort which was distinct from the cohort which their parents belonged to. In addition to the usual generational differences, Issei men were typically ten to fifteen years older than their wives, making them significantly older than the younger children in their often large families. U.S. law prohibited Japanese immigrants from becoming naturalized citizens, making them dependent on their children whenever they rented or purchased property. Communication between English-speaking children and parents who mostly or completely spoke in Japanese was often difficult. A significant number of older Nisei, many of whom were born prior to the immigration ban, had married and already started families of their own by the time the US entered World War II.
Despite racist legislation which prevented Issei from becoming naturalized citizens (or owning property, voting, or running for political office), these Japanese immigrants established communities in their new hometowns. Japanese Americans contributed to the agriculture of California and other Western states, by introducing irrigation methods which enabled them to cultivate fruits, vegetables, and flowers on previously inhospitable land.
In both rural and urban areas, kenjinkai, community groups for immigrants from the same Japanese prefecture, and fujinkai, Buddhist women's associations, organized community events and did charitable work, provided loans and financial assistance and built Japanese language schools for their children. Excluded from setting up shop in white neighborhoods, nikkei-owned small businesses thrived in the Nihonmachi, or Japantowns of urban centers, such as Los Angeles, San Francisco, and Seattle.
In the 1930s, the Office of Naval Intelligence (ONI), concerned as a result of Imperial Japan's rising military power in Asia, began to conduct surveillance in Japanese American communities in Hawaii. Starting in 1936, at the behest of President Roosevelt, the ONI began to compile a "special list of those Japanese Americans who would be the first to be placed in a concentration camp in the event of trouble" between Japan and the United States. In 1939, again by order of the President, the ONI, Military Intelligence Division, and FBI began working together to compile a larger Custodial Detention Index. Early in 1941, Roosevelt commissioned Curtis Munson to conduct an investigation on Japanese Americans living on the West Coast and in Hawaii. After working with FBI and ONI officials and interviewing Japanese Americans and those familiar with them, Munson determined that the "Japanese problem" was nonexistent. His final report to the President, submitted November 7, 1941, "certified a remarkable, even extraordinary degree of loyalty among this generally suspect ethnic group." A subsequent report by Kenneth Ringle (ONI), delivered to the President in January 1942, also found little evidence to support claims of Japanese American disloyalty and argued against mass incarceration.
Roosevelt's racial attitudes toward Japanese Americans
During the 1920s, Roosevelt wrote articles in the Macon Telegraph in which he expressed his opposition to white-Japanese intermarriages based on his fear that if they were not outlawed, such marriages would foster "the mingling of Asiatic blood with European or American blood" and in those articles, he also praised California's ban on land ownership by the first-generation Japanese. In 1936, while he was president of the United States, he privately wrote, in reference to contact between Japanese sailors and the local Japanese American population in the event of war, that "every Japanese citizen or non-citizen on the Island of Oahu who meets these Japanese ships or has any connection with their officers or men should be secretly but definitely identified and his or her name placed on a special list of those who would be the first to be placed in a concentration camp."
After the attack on Pearl Harbor
In the weeks immediately following the attack on Pearl Harbor the president disregarded the advice of advisors, notably John Franklin Carter, who urged him to speak out in defense of the rights of Japanese Americans.
The surprise attack on Pearl Harbor on December 7, 1941, led military and political leaders to suspect that Imperial Japan was preparing a full-scale invasion of the United States West Coast. Due to Japan's rapid military conquest of a large portion of Asia and the Pacific including a small portion of the U.S. West Coast (i.e., Aleutian Islands Campaign) between 1937 and 1942, some Americans feared that its military forces were unstoppable.
American public opinion initially stood by the large population of Japanese Americans living on the West Coast, with the Los Angeles Times characterizing them as "good Americans, born and educated as such." Many Americans believed that their loyalty to the United States was unquestionable. Though some in the administration (including Attorney General Francis Biddle and FBI Director J. Edgar Hoover) dismissed all rumors of Japanese American espionage on behalf of the Japanese war effort, pressure mounted upon the administration as the tide of public opinion turned against Japanese Americans.
A survey of the Office of Facts and Figures on February 4 (two weeks prior to the president's order) reported that a majority of Americans expressed satisfaction with existing governmental controls on Japanese Americans. Moreover, in his autobiography in 1962, Biddle, who opposed incarceration, downplayed the influence of public opinion in prompting the president's decision. He even considered it doubtful "whether, political and special group press aside, public opinion even on the West Coast supported evacuation." Support for harsher measures toward Japanese Americans increased over time, however, in part since Roosevelt did little to use his office to calm attitudes. According to a March 1942 poll conducted by the American Institute of Public Opinion, after incarceration was becoming inevitable, 93% of Americans supported the relocation of Japanese non-citizens from the Pacific Coast while only 1% opposed it. According to the same poll, 59% supported the relocation of Japanese people who were born in the country and were United States citizens, while 25% opposed it.
The incarceration and imprisonment measures taken against Japanese Americans after the attack falls into a broader trend of anti-Japanese attitudes on the West Coast of the United States. To this end, preparations had already been made in the collection of names of Japanese American individuals and organizations, along with other foreign nationals such as Germans and Italians, that were to be removed from society in the event of a conflict. The December 7th attack on Pearl Harbor, bringing the United States into the Second World War, enabled the implementation of the dedicated government policy of incarceration, with the action and methodology having been extensively prepared before war broke out despite multiple reports that had been consulted by Roosevelt expressing the notion that Japanese Americans posed little threat.
Additionally, the forced removal and incarceration of Japanese Americans during World War II led to severe economic consequences. Numerous Japanese Americans had to leave their homes, businesses, and possessions since they were relocated to the internment camps. This also led to the collapse of many family-owned businesses, real estate, and their savings since they had been escorted to the camps. "Camp residents lost some $400 million in property during their incarceration. Congress provided $38 million in reparations in 1948 and, forty years later, paid an additional $20,000 to each surviving individual who had been detained in the camps". Additionally, Japanese American farmers suffered greatly due to their forced relocation. In 1942, the managing secretary of the Western Growers Protective Association reported that the removal of Japanese Americans led to significant profits for growers and shippers.