[Jedi Master Pikachu]

Yes, the Italian- and definitely the German-descended population was huge. However, some families of either German and Italian immigrants or even naturalized citizens, were deported to overseas internment camps. What happened to the Japanese-descendees was much more extensive.

[Michael81Dus]

Thanks, as another FReeper said, those were suspects of aiding the Nazis, so they were not imprisoned for their ethnic heritage, but for their membership in the Nazi party or so.