I have photocopies of the Örlinghausen churchbooks for the deaths of both Johann Christoph Niemann and his widow Friederike Henriette Florentine Lüking. He died in 1878 (before Bismarck passed his first law attempting to ban the Socialist Democratic Party) and she died in 1894. If they fled Prussia to the US they returned to Germany to die. No lore about their flight in my family! I have a snapshot of the bed headboard that Anna Katrina Keiser zu Dingerdissen brought in her bridecart when she married Frans Henrich Niemann geb. Frohne in 1792. It is owned by my cousin and is in the attic of his home, the Niemann Hof in Wàhrentrup.
Frans Frohne married the widow Anna Niemann geb. Krawinkel, and took the farm name, Niemann. He was 35 and she was 64. She died about 8 years later and he married Anna Katrina Keiser zu Dingerdissen. Dingerdissen is a large Hof, not quite a village. Their children were Johann Christoph, Johann Bernhard who married a Kirchoff, and Florentine who married a Niebuhr (ancestress of the theologians Reinhold and H. Richard Niebuhr). After her death he married Anna Reue and they had a daughter who married a Ploger--maybe Plöger.