Final answer:
People of Japanese ancestry were placed in detention camps during World War II due to Executive Order 9066, which was a result of war hysteria, racism, and a failure of political leadership following the attack on Pearl Harbor.
Step-by-step explanation:
The placement of people of Japanese ancestry in detention camps during World War II was a direct result of Executive Order 9066, signed by President Franklin D. Roosevelt in 1942, following the Japanese bombing of Pearl Harbor. This order authorized the forced relocation and internment of over 110,000 people of Japanese ancestry, the majority of whom were American citizens. The internment was fueled by war hysteria, racism, and a failure in political leadership, and those interned lost their homes, jobs, and were stripped of their civil rights without any evidence of espionage or disloyalty to the United States. In 1988, President Reagan signed legislation formally apologizing for the internments and providing reparations to surviving internees.