Good ad, not a great beer.
Germans did not face the same xenophobia that Irishmen of the same period did, unless those Germans were openly Catholic, then they received the echoes of the Reformation/Counter-reformation controversy which tore Europe up so badly, because most Americans at the time were Protestant and Anti-Papist, frequently militantly so.
The American, or "Know-Nothing" party (do not ever let your opposition name your party) was generally anti-immigrant and they mostly drifted into the Republican party after 1854.
Large numbers of '48ers (proponents of a united Germany that lost in the revolutions of 1848-9 and were expelled from or invited to leave Germany) settled in the Missouri River valley of Missouri, between St. Louis and Jefferson City, the
Missouri Rhineland. These formed the core of the Hegelian "
Ein Volk, Ein Reich, Ein Fuhrer" types that supported the Union in 1861-1865, and made the war in Missouri a particularly nasty affair.
Ironically, the reputation of Germans in the Late Unpleasantness was that of unmotivated cowards who did not know how to fight. The Union XI Corps under General Oliver Otis Howard contained high numbers of German-Americans. They folded like a tent at Chancellorsville, and folded again at Gettysburg. They earned the nickname "Howard's Cowards" and "the Flying Dutchmen," and the Corps was broken up after the latter fight.