Western or Eastern traditions ?
The Western technique is described in any good furniture book that talks about the development of veneering in the 18th century. Although resawing for timber was a skilled trade, the real experts were those who resawed extra-thin boards (1/8" and 1/16") for veneers.
None (or little) of this was pit-sawing. That was the rough end of the trade, sawing deals for housebuilding. The accurate resawing was generally done with the board raised on large trestles or a fixed framework - they needed light and visibility. It was done by paired teams who always worked together (often for decades) and may have travelled around the country as a working team. It's usual to think of the guy on top (the tillerman) as being the brains of the outfit and the guy underneath as little more than cheap muscle. For cabinetry-grade resawing though, this is a disservice to the undersawyer.
The saws were frame saws, not bow saws. They had a wooden frame on both sides of the timber and were often screw-tensioned, not string tensioned. Blades were much deeper than bow saw blades (partly because suitable steel was still poor before 1759). The design of the upper tiller is distinctive between saws optimised for power or accuracy.
Water-powered framesaws are a very early innovation (medieval!) but didn't dominate the whole trade until late into the 18th century. There was a lot of regional variation as to the rate of adoption of machinery
- England was still leading America at this point.
In the Eastern tradition, it's generally a one-man task. "Timberyard" resawing was done with short squat blades and short squat sawyers the size of a small tree - these guys are sometimes said to have been the founders of sumo. They were famously strong (which in those days meant they were simply well fed). Again an outdoor trestle would have been used to support the timber when resawing as boards. There's a famous woodblock (Hokusai?) showing sawyers at work on such a frame.
Fine resawing was done by the final carpenter, not a specialist. Saws were more like a ryoba or fine-toothed anahiki and had long rod handles. The timber was supported on low horses and the sawyer worked above it (often holding it down with their bare toes, which I've never been too happy about doing!). Typically for fine work only a few strokes would be taken, then the beam turned over and sawn from the other side for a few strokes.