David,
the revolution of 1848 really had little to do with emigration of
people from Oldenburg. Sure, there was some turmoil and the archduke
granted a new Verwaltungsgesetz (communal law) but sufice it to say
that economic reasons were always way on top with the immigrants who
came to America. Bismark and the Prussians really had no bearing on
the Oldenburgers until the forming of the Reich in 1871 and even then
very little. The Kulturkampf had some repercussions with the RC church
and the clergy but that did not cause people to leave the country.
So, if you get back the village of emigration and search in the local
history there, you'd find that the folks who left invariably were
Heuerleute who owned nothing but were yearning to have a piece of
land. For that they came to America. The Industrial Revolution would
be more of a reason for their emigration not the political one.
Fred