Many thanks for this. I was at my local library today tracing Joel and Jacob Heckman's male children in the 1900, 1910 and 920 Ohio census, with some success. I noticed Susanna Wehrly Heckman still alive in the 1920 census with son John and wife. But the marriages you give open a whole new territory.
What would be very helpful is, if you had these families too. I will be glad to exchange my census results for the Heckman's, such as they are, incomplete; but you probably have all that already. (e-mail is at firstname.lastname@example.org, if that would help accomplish more)