Hi Douglas, are you just starting out? Where do you live? Have been finding a few records for some of your family members and some I already have in my files.
Linda Corupe spent a long time transcribing the records of John Collins Clark of Ernestown (1786-1864). Your Clark's were relatives and friends of John C.; he refers to your ancestor John Clark born abt 1809-1811 time frame as being the son of "Robert Clark the 2nd". That reference is in Linda's publication on her page 54 near the bottom of the page when John C. mentions that your John Clark married Hannah Hicks on Feb. 18, 1835.
If I have my genealogy correct then, your direct ancestor Robert Clark the 2nd (father of 1809 John) was an older brother to John Collins Clark. The Matthew Clark you have listed as a father to your ancestor John Clark was actually a brother to 1777 Robert Clark, and to 1786 John Collins Clark, therefore Matthew would have been your 1809 John Clark's uncle. I have Matthew Clark's dod as June 8 1848, not 1857.
Father to Robert Clark, Matthew Clark, and John Collins Clark was Robert Clark (the first) born 1744 at Quaker Hill, Dutchess County, New York; he was married to Isabel Ketchum. Robert died Dec. 17 1823 at Ernestown; Isabel died Dec. 6, 1809 at Ernestown.
I am more than willing to help you and provide other info- just let me know what you are looking for exactly and how much work you have already done, or not! I also am positive there are other researchers on this board and descendants in same Clark line who might be able to help you.
I am not related at all; have worked on Lennox and Addington and Frontenac and Hastings County families past 15 years. Started out working on my own families and just kept researching....
Thx from Nora