I did a quick search for Donald Berndt in Wisconsin and came up with about a dozen different persons from several dates of birth ranging from the middle of the 1800s to late in the 1900s. To get closer would require at least some approximate dates. The SSDI has several with the last name spelled as Berndt, Barndt, Behrndt, Brant, etc. These are all spellings that I have run across in searching for my own Berndt family, since my mother was a Berndt. Have you searched any Census records? One of my Berndt family was born in either Indiana or Michigan, and died in Hawaii. I am still searching for more info on him. Approximate dates would be a tremendous help, even if they were spread over a couple of decades!