After Pearl Harbor, Americans were infuriated that the Japanese could do such a thing to "neutral" America. People found a scapegoat: innocent Japanese Americans. Many were accused of being spies for the Empire of Japan. The real reason, though, is President Roosevelt created Executive Order 9066, which congress was happy to pass. Many congressmen were also fervent about punishing the Japanese, some even going as far as to say the U.S. should get rid of the Japanese like the Germans were getting rid of Jews. Thus, it was anger that drove politicians to create these inhumane camps.
