I e-mailed you directly, but then got to looking at my records and thought I'd post the info here so others can see it, eventually.According to the Koepke Genealogy I received from the Amherst Historical Society, Jacob is the son of Karl (Charles) Johann Friedrich Koepke and Henrietta Caroline Dorothea Langhoff; he was b. 11 May 1871, died 27 March 1951. Married Caroline Louise Johanna Bruse, with children John, Carl, Albert, Elizabeth and Paul, then second spouse Elizabeth Hanley Everitt and had Frank, Luther, Daniel, Jacob Jr., Caroline, Lillian, Eleanor, and Amelia.Karl and Henrietta had daughters Emelie and Hermyne, who died as infants/children.
My line connects through Karl Koepke's second wife, Elizabeth Werner, who bore John, Catherine and Anna.
I've got more, if you'd like to exchange info.How are you connected?