I think that a better diet was a major factor - the rural population had access to more and better food. Here's what my grandfather said about the farms in central Wisconsin during his youth [about 1875-1900]. He grew up on a small, not especially prosperous family farm:
"The farming was largely subsistence. People took their grain to the grist mills and had it ground into flour. The grains taken were wheat, rye, maize, and buckwheat. ... Almost everyone had a patch of sugar cane [sorghum]. ... A garden was a necessity. This was well manured and plowed early. The first thing to come on the menu was parsnips which had been left in the ground all winter and dug as soon as the frost was out. Next was asparagus and pie plant [rhubarb]. ... It was an aim to have the first new potatoes and green peas by the fourth of July. Between the time of pie plant and new potatoes, there was the season of "greens" -- dandelions and nettles, also, later, pig weeds and red root. ... There were squashes, pie pumpkins, rutabagas, beets, carrots and cabbage to be put away with the potatoes in the cellar. During the summer, apples had been dried, sweet corn dried, jams and jellies made, and some had begun to can fruits in mason jars. By my day, most every farm had an orchard with apple trees and sometimes with cherries and plums. Everyone expected to grow their own strawberries and many had currents, gooseberries, raspberries and blackberries. ... All farms had cows, fowls, turkeys and hogs; many had geese and some had ducks. ... Most every farm had sheep. ... As an addition to the diet, most of the farmers did some hunting and fishing. Many looked for wild berries and expeditions were made into the scrub pine regions further north in the blueberry season. Most of the farms had a melon patch where they grew both watermelons and muskmelons. In the fall, hazelnuts and hickory nuts were sought and put away for winter use as was a stock of pop corn."
