I think we all use much stronger loads than our ancestors. Better metals, more disposable cash, ease of obtaining power are a few reasons. This is just a hobby for most of us, the pioneers very life depending on not running out of powder, so i think they used it, like everything else, sparingly.
My best friend uses a 54cal and 50grs ffg to take whitetail. He's killed 2 recently with no problem.
If you think back to the beginning of the metallic cartridges, remember the 44WCF, aka 44-40?
This cartridge was considered the best thing Before sliced bread and took game up to moose with the "hump" shot, and was popular thru the 1950s.
This well respected round used 40 grains of fine powder and a 200gr lead bullet, for around 1200fps.
I believe it's in Ned Roberts book where an old possibles bag is shown with several different powder measures... do you think the hunter of old owned several different rifles?
IIRC, Roberts talks about a small game load, a large game load, and a "Bear" load.
Maybe that's where the phrase "loaded for Bear " comes from.