Gabriele,
I am also a NIEHAUS. Mein Urgrossvater Heinrich NIEHAUS aus Neunkirchen bei Voerden, Amt Damme, Oldenburg, geb1845, +1895 in Cincinnati, Ohio, U.S.A. I have records of our NIEHAUS Catholic ancestors back to 1720, all living in Neuenkirchen and then in Cincinnati. We live now in Charlottesville, Virginia.
Do you see any connection to your NIEHAUS ancestors?
Bob Niehaus