Other questions that would be interesting are:
How did the government convince German immigrants that their new country was going to war with their homeland?
Was there any camps? Like the Japanese after Pearl Harbour.
Was there any German related Terrorism on US soil?
How did non-German citizens treat them?
How did the Jewish population act towards the Germans in cities like New York, were the communities were very close?
I understand that the US entered both wars at a late stage. Why did the USA sell to the British and not the Germans?
You get the gist. There must of been millions of Generational and German born citizens in the States at the time. What was their life like?
One of the first things you need to think about is why the Germans came over to the US. The vast majority of immigrants came after the failed Democratic revolutions in the 1890s, so they wanted to live in Republican state. That being said while these Germans hated the Kaiser they didn't want war between the US and Germany, simply due to connections back home. This produced huge strains which would impact how they were treated and how these Germans would act in WWII. Anti-German sentiment was so bad that 16 US states banned speaking German in public some states even required that people change their German names to American ones (Smicht to Smith), thousands of beer halls in the US were shutdown or even burned down, Germans were banned from having certain jobs (strategic/Gov't), internment camps were also set up, there were numerous cases of Germans being killed to seriously maimed due to 'Not being patriotic'. For example a man was tarred and feathered for not buying War Bonds, another man was lynched for 'not being American/Patriotic', and a pregnant woman was reportedly nearly beaten to death for speaking German with a local priest ( Although I have read this mentioned in numerous books I haven't hit any primary sources on it). President Woodrow Wilson even called German-Americans 'Alien citizens'. This caused two things 1) Need/Desire for German Americans to prove their loyalty, 2) complete erasure of German Culture. Point one can best be seen in the case of Henry Gunther a German-American who was killed 15 seconds before the Armistice charging a German machine gun, his death was so controversial that it caused a investigation as to why nobody stopped him and why he did it. As to point two close to fifth of the US population (60 Million people) have German ancestry but despite this less than 5 million have German names and less than two million can speak German. So by the time that WWII came along most German-Americans were so disenfranchised with their culture that they no longer saw them selves as Germans but where in stead were Americans.