Ellen Marten - Source Match Linking from proven Lines

I have been folllowing an ascenscion of lines from Known Characters proven to match in my lineage (by following their trees up to a topical match).
I seem to have found a 'Key' lineage for MARTIN that has fallen as close as
Robert Martin *
B:1764 Ireland
D:1867 Jackson Co., GA
and
Susannah Senter Key *
B:1778 Bedford, Virginia, United States
D:about 17 Jun 1886 West Point, Troup, Georgia, United States