Ok. At least one of the knives you posted has riveted handles, so it is not, contra your assertion, probably the 1840s - the proposed date of the knife in question. Ergo, it doesn't actually provide evidence to back up your claim that your knife dates prior to the Civil War. I was not attacking your knife or defending it, just observing that the knives posted don't bolster your position they way you seem to think they do.
Incidentally, while it is hard to tell from pictures, I'm really not seeing much that looks like hammer marks on those knives anyway - the first two just look pitted from corrosion, the third - which I discover is the Cephas Hamm knife - has remnants of file teeth underneath staining and pitting (I like that knife quite a bit, btw. Thanks for posting it, as I was unaware of it until now), and the fourth is just a bad grinding job - it looks like it was done with an angle grinder and I suspect that it is a fairly recent piece from somewhere outside of North America. The form and grind job seem vaguely familiar, and I note it has an intact sheath. I do have some blacksmithing experience, including grinding filing hammer marks off knives, as well as restoring old tools, so I do know from first-hand experience what hammer marks, forge scale, and rust pits look like.