Hi, Well, we've been researching for over 46 yrs now, and have yet to be able to document most of our hard-won data. Our PC crashed recently & most of our source notes have vanished, but the info of the HICKMAN Bible is on the internet, in Ancestry's fam tree/groups, on familysearch.com the LDS site, on HICKMAN web pages & other sources.

Our KETCHUM data has kind of sorted itself out over the years, our lines stem from Isaac Martin > John Jackson > Joseph > Edward > Jacob Israel > ad finitum etc. There aren't that many David KETCHUM's to research, and I can say we have, over the yrs, checked most of the early one out. This David is born at the right time, in the right locale, is listed in other Hickman recs, has the same children, has the same wife ("Patey") etc. If it walks like a duck, quacks like a duck, looks like a duck, then probably it is a duck...
So in answer to your question, do we have "absolute documentation" (whatever that is, with early recs being what they are...) then, NO we don't. But at least you'll have fun trying to find this documentation, which is almost non-existant at this point.
One source is the DAR records, but even they are flawed, big time! Even some of my own lineages have major errors in the DAR Lineages records, the BLOCKER family from Edgefield Dist SC etc. So nothing is absolute proof, not even grave stones, death certs, family Bible recs, bapt certs etc; all are dependant upon what other people write down at the time, which may or may not be correct.
Hope you have good luck in your hunt... Kathleen