My great-uncle is searching for his family and I offered to assist him. His mother is Clara Erhardt (1894-1962). She was born in the White Bear Lake/Oneka area of Minnesota to Lewis/Louis Erhardt (b. 1853ish) and Mary C Nelson. Louis' father's name was Moritz or Morris Erhardt, probably born around 1811.
We do not know who my uncle's father is, but we are fairly certain his last name is Dillon. The last I can find of Clara before her death in 1962 is in the 1920 Federal Census, where she was working as a seamstress in St. Paul, MN. We know, from my uncle, that she moved to Kansas City, MO at some point, and had him in April of 1923. I personally believe she moved after she became pregnant. He claims he was born in a "Home for Unwed Mothers", and I believe she moved to Kansas City for that reason (as KC was a haven for unwed mothers around that time).
On my uncle's 1930 Federal Census, his father is listed as being born in Minnesota.
I do know that one of Clara's sisters (Gertrude, Luella, Mary, or Mabel) did come to visit at one point, so some contact was kept. I am hoping that some of the family's descendants may have some insight into who my uncle's father is and how to find his family. I'll even take rumors at this point. My uncle is 91 and in very good health, but he is seeking some closure on something that has been mysterious to him his entire life.
Secondarily, I wouldn't mind having more history on the Erhardt family in general.
Thank you all for your help.