A friend and another forum member picked this up for me at a show back east. I’ve showed a couple other collectors and they agree with me that it's either Civil War or possibly Indian Wars. I think with the braided Turks Head and slide it may be an officer's knot. There is a maker’s mark but do to the age it can't be made out and it's a pretty big knot at 21" long. I like it and it's in great shape and fairly pliable. I would appreciate any thoughts from the other sword guys here.

It looks Civil War era to ~1872 to me, maybe an officer's knot but the regulation officer's knot was a gold bullion affair...

I agree. It is certainly a nice looking knot. My best guess would be just post CW... I like it.