Richard, First, thank you for taking the time to respond to my inquiry.It's such generosity as yours that is enabling me to compile my family's history.
As to your question regarding family of Silas Clark, I only a couple of days ago discovered this family in Ohio, along with others of my family from Cornwall.Apparently they settled Portage County as a family group.
The only member of Silas's family I could find living in the area in 1880 to date is his younger brother Marcus Birdseye Clark, who was still living in Nelson, Portage County, Ohio.Nelson appears to be where the family put down their roots when arriving in Ohio.I suspect they migrated about 1820.His father is Wells Clark, and his siblings are: Tabitha Maria; Garrett Wells; Charlotte Polly; Harriett Rogers; and Mary Pinkney.
To date I've only found the marriages for Silas (Mary Ann Page, Portage, Ohio); Marcus Birdseye Clark (Arabella Raymond, Portage County); Clarissa (Hill D. Mercer, Nelson Portage); Charlotte (Garry Gates, Portage).
I'm finding Portage County a difficult place to research on-line, and have to travel 80 miles round-trip to access the census with ancestry.com at the research library.Problem is, ancestry.com is over-rated, as they are missiing many of the townships in their census files.