No, they weren’t Fourty-Eighters. They were far from being revolutionaries. They came over in the early 1870’s.
Thus it follows that they were also a product of the liberal revolution that was put down 20 years earlier.
So this is different from the traditional American historical Palatinate settlers, who came between 1710 and 1750, for similar reasons: but they were Protestants, mostly followers of Alexander Mack.
And those are the original settlers of Western North Carolina and Eastern Tennessee.
And the originators of the Revolution, the American Revolution - you might want to familiarize yourself with the Battle of Alamance and the Regulators.
And the idea of Catholics being "victims" is absurd - while it's true that German principalities could choose official Lutheranism or Catholicism in the aftermath of the Treaty of Westphalia but typically for Catholics that simply meant moving a couple of towns over and re-settling.
For Anabaptists, Pietists and other Protestant sects it meant leaving Germany on the first boat up the Rhine.
That part of history is well known and documented.
You should note that the America that was founded reflected their attitudes of religious freedom, no State church, and thoughtful reflection on what is true and what is not rather then slavish adherence to dogma promulgated by "authorities".
This is the essence of what was created. Nothing else could have stood in a Protestant America.
And America WAS Protestant. And we didn't have a non-Protestant president until that Rat SOB John Kennedy.
And the despicable things he did or his compatriots like Norbert Schlei reverberate to this day, and will be the death of America.