My great grandfather Heinrich Christoph STRADTMANN was born in Celle, near Hannover, in 1820. I've been unable to establish any blood relationship between him and anyone else with the STRADTMANN name in that area. There have been indications that his parents changed the family name at about the time of his birth, perhaps from STROTBAUM, and that they originated in some other area of Europe. Always looking for anyone else who may be related, since we are a very small family here in Pennsylvania (just my son and me left with the name).