It was the Japanese Americans. This is because Japan bombed Pearl Harbor in America, which made Americans suspicious of the Japanese Americans.
Hope this helped. Lmk if you still have a question or this explanation wasn't clear enough. :-)
Celsius, people in Europe would use Celsius
...he believed in the limited use of federal power but also that states were not truly sovereign.
I assume by "feds" you mean the federal government. They enforce national laws. While the states can make their own laws they must do so by abiding by federal law. For example, a state cannot make murder legal.