A total of 11,507 people of German ancestry were interned during the war. At the start of World War II , under the authority of the Alien Enemies Act of 1798, the United States government detained and interned as enemy aliens more than 11,000 German nationals, as well as detaining a small number of US citizens of German ethnicity, either naturalized or native-born. The aliens included immigrants to the U.S. as well as German nationals stranded in the U.S. by the hostilities. In many cases, the families of the internees were allowed to remain with them at internment camps in the U.S. In other cases, families were separated. Limited due process was allowed for those arrested and detained.
A total of 11,507 Germans and German-Americans were interned during the war. This group was overwhelmingly composed of German nationals. Together this group accounted for 36% of the total internments under the Justice Department's Enemy Alien Control Program. By contrast, an estimated 110,000-120,000 Japanese-Americans were forcibly relocated from the West Coast and incarcerated in concentration camps in the interior run by an agency of the Department of Defense. Some Japanese Americans were investigated and later detained in DOJ camps under its Enemy Alien program.
In 1942 there were 695,000 Italian immigrants in the United States. Some 1881 were taken into custody and detained under wartime restrictions; these were applied most often by the War Relocation Authority to diplomats, businessmen, and Italian nationals who were students in the US, especially to exclude them from sensitive coastal areas. In addition, merchant seamen trapped in US ports by the outbreak of war were detained. Italian labor leaders lobbied for recognition as loyal (and not enemy aliens) those Italian Americans who had initiated naturalization before the war broke out; they objected to blanket classification of Italian nationals as subversives.
During WWII, the U.S. Government interned at least 11,000 persons of German ancestry. By law, only “enemy aliens” could be interned; however, with governmental approval, their family members frequently joined them in the camps. Many such “voluntarily” interned spouses and children were American citizens. Internment was frequently based upon uncorroborated, hearsay evidence gathered by the FBI and other intelligence agencies. DOJ instituted very limited due process protections for those arrested. Potential internees were held in custody for weeks in temporary detention centers, such as jails and hospitals, prior to their hearings. Frequently, their families had no idea where they were for weeks. The hearings took place before DOJ-constituted civilian hearing boards. Those arrested were subject to hostile questioning by the local prosecuting U.S. Attorney, who was assisted by the investigating FBI agents.
Pursuant to the Alien Enemy Act, the alien enemy program targeted all persons of “enemy ancestry” during World War II—German, Japanese and Italian—because such persons were considered disloyal by reason of their ancestry.
On February 19, 1942, Roosevelt signed Executive Order 9066 authorizing the military to limit movements or arrest suspected alien residents. Although applying primarily to Japanese, it also involved the arrest of 3,200 Italians resulting in the incarceration of 300.
Shocked by the December 7, 1941, Empire of Japan attack on Pearl Harbor, Hawaii that propelled the United States into World War II, one U.S. government response to the war (1941-1945) began in early 1942 with the incarceration of thousands of Japanese Americans on the West Coast and the territory of Hawaii. Approximately 120,000 Issei (first generation, Japanese immigrants) and Nisei (second generation, U.S. citizens) from the U.S. West Coast were incarcerated in War Relocation Authority (WRA) camps across the country--based on Executive Order 9066 (Feb. 19, 1942). Through separate confinement programs to the WRA, thousands of Japanese, German, and Italian citizens in the U.S. (and in many cases, their U.S. citizen relatives), classified as Enemy Aliens, were detained by the Department of Justice (DOJ) through its Alien Enemy Control Unit
History has shown that the U.S.’ efforts were conducted not just to legitimately secure the region due to fears that Germany might seize power in Latin American countries or Japan might attack and occupy the vital Panama Canal Zone––essential to rapid passage between the Atlantic and Pacific oceans during the World War II––but also due to prejudice. There were Latin American and U.S. businessmen who begrudged the success of Japanese, German, and Italian nationals and the war provided an opportunity to remove this source of competition.