Looking for Hahn Wagner Schultz OR Zimmerman Geneologies

I am able to trace back my ancestry only as far as my great grandfather, Carl Hahn. It seems that Carl was, at one time, a wealthy merchant in Berlin. He came to the United States in the 1870s and settled in North Dakota. He had several sons, including Robert, Albert, Alfred, among others. Daughters included Frieda and Elizabeth. I am attempting to put together a family tree for my father, Wayne, who is now 83 and really doesn't know a great deal about his family.