The anti-German hysteria was mostly during the First World War. Nebraska banned the teaching of German, sauerkraut was renamed 'victory cabbage' or some such nonsense, decent beer became hard to find. Many with German names changed them during the Great War.
As far as the alleged racist basis of this, Chinese were *not* relocated.
~200k Germans and Italians together were interned, however all of these were enemy nationals.
A handful of people from smaller enemy nations such as Croatia and Romania were registered and monitored. Most were not because there were no Soviet-style population controls in the USA at the time -- unless these people came forward there was no finding them.
d.o.l.
Criminal Number 18F
Well we know what one German-American did, lead the Allied forces against Germany (Eisenhower).