Hi! I'm a descendant of John W. Reichwein B:Sep 1850 in Waldbech, Germany. I don't know the reasons behind the spelling changes, but in a related branch of Reichwein's (I don't know how they relate to me other than by marriage and suspicion) there are spelling changes in the same family. Probably due to illiteracy? Anyway, Peter Reichwein, B:Dec 1839, Prussia, Germany, D:26 Nov 1907, Frackville, Schuylkill, PA, had 13 children with his wife Margaret Stahl. Of those children, the first five are spelled Reichwein, the last 8 are spelled Reichwine. That was all before 1900, so your guess is as good as mine!