This is pretty much the case. I farm in an area that was homesteaded late for most of the prairies (early 1900s), and that was all done with horses. I have an uncle that just recently passed away that was part of the transition to mechanical power, and their first tractor was gas-powered one since it would start in the cold. That would have been about WW2 time since he was a teenager when it showed up and they got rid of the draft horses.