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Executive Order 9066 and the Japanese Exclusion Act of 1942 which ratified the order were enacted in response to the bombing of Pearl Harbor and resulted in the relocation and internment of 120,000 people of Japanese and Japanese-American descent. Fred Korematsu, an American citizen of Japanese descent, refused to go. The Court found the act to be constitutional and that Japanese-American citizens did in fact represent a threat to national security. The US government eventually issued a formal apology for internment and provided token financial restitution for affected families in 1988.

Justice Jackson in his dissenting opinion in Korematsu said, "[The] judicial construction of the due process clause that will sustain this [executive] order is a far more subtle blow to liberty than the promulgation of the order itself... the Court for all time has validated the principle of racial discrimination in criminal procedure and of transplanting American citizens. The principle then lies about like a loaded weapon ready for the hand of any authority that can bring forward a plausible claim of an urgent need."