"A horse exerting 1 horsepower can raise 330 pounds of coal 100 feet in a minute, or 33 pounds of coal 1,000 feet in one minute, or 1,000 pounds 33 feet in one minute. You can make up whatever combination of feet and pounds you like. As long as the product is 33,000 foot-pounds in one minute, you have a horsepower. [sic]"
https://auto.howstuffworks.com/horsepower.htm
If geared properly, that means a Tecumseh 2.5 hp could lift 825 lbs 100 feet in a minute! I find this hard to beleive, but after seeing what a Tote Gote can pull with only 3hp, it doesn't sound far off.
If they had used donkeys in mines, it would have been Donkey Power!
Also, small engine manufacturers got in trouble a few years ago for overstating their HP claims, there is more on the web about this elsewhere, but this is why you see modern small engines rated with things like "net torque" or "equivalent to X Horsepower" or "formerly X hp" on engine decals nowadays instead of a HP rating.