President Trump followed the exact procedure President Roosevelt followed in 1941, BEFORE the US declared war on Japan. The military immediately detained Japanese citizens, they were held for years in detainment facilities, without any type of trial.
The U.S. declared war on Dec. 8, 1941. It was
after war was declared that the Japanese were detained. In 1988 the government apologized for the injustice. So I would not consider this to be precedent for Trump’s procedure.
In his speech to Congress, President Franklin Delano Roosevelt declared that the Japanese attack on Pearl Harbor on December 7, 1941, was "a date which will live in infamy." The attack launched the United States fully into the two theaters of World War II – Europe and the Pacific. Prior to Pearl...
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In February 1942, just two months later, President Roosevelt, as commander-in-chief, issued Executive Order 9066 that resulted in the internment of Japanese Americans. The order authorized the Secretary of War and military commanders to evacuate all persons deemed a threat from the West Coast to internment camps, that the government called "relocation centers," further inland.
On March 29, 1942, under the authority of the executive order, DeWitt issued Public Proclamation No. 4, which began the forced evacuation and detention of Japanese-American West Coast residents on a 48-hour notice.
In 1988, Congress passed, and President Reagan signed, Public Law 100-383 – the Civil Liberties Act of 1988 – that acknowledged the injustice of "internment," apologized for it, and provided a $20,000 cash payment to each person who was incarcerated.