Thanks for your quick reply. Quite frankly, I'm not sure who my ggrandfather was related to, but, I have always had the impression that he had few relatives in the U.S. According to various records, Christian was born on 1 Jan 1850 in Schleswig. He came to the U.S. in 1866 at age 16, supposedly to avoid military service. Upon arrival in the U.S. he came directly to Dallas County, Iowa, because, according to family stories, he had a relative there named Peter Hansen. According to the 1925 Iowa census and his death certificate (he died 27 Jan 1927) his father was Chris Hansen and his mother was Elnora or Nora Bunder.
I have not been able to determine where in Schleswig he was born, but thought that I might have some luck tracing the family through the Bunder name rather than Hansen since it is much less common than Hansen. I would like to go to Schleswig and look around to see if I could find out something about the family, but with no birth place, I think that could be quite futile.
If any of this strikes familiar with anyone would be glad to hear from you.