Christian Gerdes Sartorius is my great-uncle. I have found this spelling, Satorius and Zerdes. Father, Peter born 1820 Wessin, Rhineland, Germany. Mother, Gertrude Zerdes born 1820. Sisters Catharine, Caecilie, Anna, Agnes, Elisabeth and Gertrude. Christian (Chris) was the youngest. The family came over from Germany in 1867, and farmed in Cedar County, Nebraska.
I have not been able to find them in Germany. Most of the information was found on census and immigration records. Chris married Anna Bergmann. They had two daughters Gertrude and Beatrice and one adopted son, I think named William. Is this your family too?