Love all the stories about Oldenburg during the World Wars.
My ancestors all emigrated before that, though. One of the reasons I started getting seriously into genealogy was to find out why.
The German community in central Missouri that was formed from this emigration started in the mid 1800's, and I suppose it was mainly do to the German Revolution of 1848 and subsequent rise to power of Otto von Bismarck and the Prussians, or the Deutsches Kaiserreich.
What was the environment like in Oldenburg during this time period that caused so much emigration?