From what little I know all historic trade knives, swords, hatchets, bill hooks, cleavers, and such were largely forged into shape either by hand or with machine help through the early 1800s. By design or as a result their cross section often or usually looks wedge shaped. Some may have an area from the spine a third or even halfway down that does not taper much of at all (a cleaver) but there is no abrupt line where it tapers to the edge on original historic knives through the early 1800s, methinks.
In contrast many knives today are ground from flat stock. As a result, in cross section, if viewed edge up, they look like a narrow house. Parallel edges then an abrupt steep roofline going to the edge. In some cases a hollow grind. I see this style in catalogues of some suppliers with curly maple slab handles, called “trade knives.”
When did this style of knife making (looks like flat stock with a grind) first become common? In kitchen, or in military, or in sporting knives?