A Japanese Americans were held in internment
camps because they

Many Americans worried that citizens of Japanese ancestry would act as spies or saboteurs for the Japanese government. Fear — not evidence — drove the U.S. to place over 127,000 Japanese-Americans in concentration camps for the duration of WWII. Over 127,000 United States citizens were imprisoned during World War II.

d.

the northwest territory became the most densely populated area in the u.s.