The earliest "pattern" that I know of was the 1849 Rifleman's knife, which may have been issued as of 1841-1845...,
From what may be gleaned from records at a frontier trading post, namely George Morgan's store in Kaskaskia in the 1760,'s, it appears the guys with rifles preferred an inexpensive butcher knife. That was also the case with Meeshach Browning, author of Forty-four Years in The Life of a Hunter, which was penned after 1800, and he too preferred a butcher knife. I mention this wide range of dates, as it seems to show an established trend.
However, we don't know if that was preferred because they had a choice, or if the best knife from what was available was a good sized butcher knife. Today we see all sorts of custom made knives, but whether that was the norm, or the trading post butcher knife was the norm, is anybody's guess.
I prefer a good carbon steel, plain, butcher knife with small steel pins. To be even more accurate, I really should have a half-tang, knife, with a boxwood handle, and two, small steel pins, but mine is full tang, with three pins in a yellow poplar wood handle.
BUT I'm very Scottish, and such a blade is sharp, and inexpensive, which I like.
LD