How many German born or 1st generation Americans of German decent actually went to Germany to fight for Nazi Germany in WW2? Were there any documented American fighters of non-German decent that fought for Nazi Germany?

by EndsWithMan

How did Germany handle these troops? Did they have units of foreign fighters, or did they assimilate them into regular German units?

Searocksandtrees
[deleted]

A follow up question: does anyone know how accurately Kurt Vonnegut portrays Howard W. Campbell Jr, an American Nazi, in Slaughterhouse Five?