According to usconstitution.net, the Constitution was not originally written in German. (It didn't seem to remark on whether it was translated, distributed, etc.)
However, if you check out old cemetaries in Iowa, Wis., Minn., you'll probably see some headstones written in German, depending on the community. This practice ended, as you might guess, early in the 1900's. German WAS spoken in homes and communities.
Distrust and even hatred of recent immigrants is nothing new. When waves of German, Italian, and Irish immigrants came in, the people already here very upset the these dirty newcomers would disrupt the status quo. And now the descendants of those same immigrants are part of the status quo.
Of course, this has nothing to do with massive illegal immigrants.