Why were Japanese-Americans interned during world war 2?

Answer 1

Fear.

After a huge number of Japanese immigrated to the US, people felt threatened because of farm and labor competition. A wave of anti-Jap prejudice spread, mostly in California. After Pearl Harbor, some people suspected Japanese-Americans were spies sending intelligence to Japan. Officials were concerned that the Japanese, especially the ethnic, would be more loyal to their homeland than to America. The Niihau Incident, immediately after Pearl Harbor, involved a Japanese and two Hawaiian-born ethnic Japanese on the island of Ni'ihau violently freeing a downed and captured Japanese naval airman, attacking their fellow Ni'ihau islanders in the process.

Source: Wikipedia

Answer 2

Japanese-American internment was the forced relocation and internment by the United States government in 1942 of approximately 110,000 Japanese Americans and Japanese residing along the Pacific coast of the United States to camps called "War Relocation Camps" (a polite way of saying Concentration Camps) in the wake of Imperial Japan's attack on Pearl Harbor.

Following the Japanese attack on Pearl Harbor in December 1941, the United States was gripped by war hysteria. This was especially strong along the Pacific coast of the U.S., where residents feared more Japanese attacks on their cities, homes, and businesses. Leaders in California, Oregon, and Washington, demanded that the residents of Japanese ancestry be removed from their homes along the coast and relocated in isolated inland areas.

While the threat from Japanese spies and saboteurs was real, it was primarily the distrust many Americans felt of the mysterious Japanese culture. Combined with virulent Propaganda against the Japanese enemy, it created a dangerously hostile situation. Some top military leaders (later known for undisguised racial bias) were allowed to contravene the rights of loyal Americans. Years later, some were compensated for their hardships, albeit both belatedly and inadequately.
Pearl Harbour led to the internment of the Japanese Americans because it scared the American citizens into being sucpisious of any Japanese person, and the government's solution was to place the Japanese Americans in internment camp so no uprisings would occur.

Answer 3

The goverment thought that they might have been spys or something along that nature

Answer 4

Many Japanese Americans and Japanese Canadians were interned for the duration [of WW2 because it was thought they had the potential to be saboteurs or spies.