Question

Why were the Japanese Americans interned in 1942?

Answer 1

There was already prejudice against the Japanese before that time.

Explanation:

Many Americans would have trouble separating Japanese from Chinese. There was strong anti Chinese immigration laws in the late 1800s. Japanese laborers were sought by employers when the Chinese were banned. As early as 1893 California tried to make segregated schools for Japanese children. The Japanese government protested.

California successful created segregated Japanese schools in 1906. Japanese were banned from purchasing land in California in 1913.

Many Japanese immigrated to Hawaii and California as laborers. Japan was persuaded to stop issuing laborer passports by 1907.
In 1924 immigration law banned most Japanese from immigrating to the United States.

There was ongoing prejudice against the Japanese in California. After the Pearl Harbor attack Hawaii did not remove or intern large numbers of Japanese from the Hawaiian Islands. Internment was mostly from California.

Internment basically treated internees like Prisoners of War because there was a written international standard for that. As a percentage many more Japanese Americans were interned than German Americans.

Large numbers of Japanese Canadians were interned in Canada.

https://en.wikipedia.org/wiki/Internment_of_German_Americans

https://en.wikipedia.org/wiki/History_of_Japanese_Americans

https://en.wikipedia.org/wiki/Internment_of_Japanese_Americans