If you have the birth year of Marcellus David Thacker and the location, state, county, and or city, that type of information would help tracing back to the earlier ancestor you are asking about. Any other birth, marriage or death dates for father and grandfather along with their location, if you have it, would help as well.
My mothers mtDNA line traces back to a Mary Clark who was born about 1590 in Hingham, Norfolk, England 52.5791° N, 0.9828° E.
Probably not your ancestor, but possibly of some interest.
