Surmann/Suhrmann and Sandmann

Looking for the parents of Clemens Surmann (aka Suhrmann) and Josephine
Sandmann. I believe Clemens was born in Oythe on 11 Dec 1825. Josephine
Sandmann was born in Oythe on 22 Sep 1826. I'm not sure if these two
married in Germany or the US. Clemens arrived in the US on 27 Oct 1852.
Clemens died 13 Sep 1896 in Cincinnati, Hamilton Co., Ohio and Jospehine
died 08 Jun 1887 , also in Cincinnati.

Any help in finding the names of the parents is greatly appreciated!!

Have a great day!