Well I am not exactly sure. The 1920 census says that they came from West Prussia. Here is the Census; Abel, William (Head of Family) 34 Yrs (West Prussia) Abel, Anna(Wife) 30 Yrs (Wisconsin) Abel, William (Father) 76 Yrs (West Prussia) Abel, Mathilda (Mother) 66 Yrs (West Prussia) Abel, Arthur (Son) 8 Yrs (Wisconsin) Abel, Alma (Daughter) 6 (Wisconsin) Abel, Ernest (Son) 4.5 Yrs (Wisconsin) Abel, Gertrude (Daughter) 1.5 Yrs (Wisconsin).
I don't see a Henrietta though. This family immigrated between 1891-1898. Ernest Abel would be my gandfather while the two william able would be my great grandfather and great great grandfather respectively. It would appear from this that my great great grandfather william was born around 1944 while his wife Mathilda was born around 1954.