They healed sick people sell medicine. Provide medical treatment. Perform surgery.
potions to cure illnesses in the olden days. usually using some kind of herbs or animals part.
In America, almost everybody was a farmer, either the farm owner or farm labor. There were some skilled trades, like blacksmithing, carpentry, grain milling, bricklaying. There was some rudimentary local industry, like shipbuilding, brick making, rope walks. There were gunsmiths, making firearms, none of which were of the identical caliber as any other gun makers, and none of which had interchangeable parts. There were powder mills, to make gunpowder. There were artisan type professions. Most furniture was either home made, or built by cabinet makers. Carriages and wagons were built by carriage makers. Wheelwrights were specialists who made or repaired wagon wheels. Few people lived in towns, and most towns were small. The largest city in America was Philadelphia, over one hundred years old, with 60,000 people. In towns there were lawyers and what passed for doctors, apothecarys (druggists), and shop keepers. Most stores were general stores, which sold every kind of merchandise.