I am seeking any info on the Sidney Wanzer branch that founded the Wanzer & Sons Dairy in the Chicago area. I have found this family in the 1880 census and they list a Bertha Wanzer as Sidney's daughter. She is not found in any later census and I am interested in her and who she married. I bought a copy of the book by William David Wanzer, but she is also not listed in it as one of his children. Does anyone know why? I believe that my father is Bertha's grandson.