In the 1750s, Scotch-Irish and German settlers entering Perry County found fertile limestone valleys such as Pfoutz and Shermans Creek along what are now Route 17 and 274, and began farming by girdling trees to expose virgin soil for corn and grains, building lean-tos and cabins from dead timber, relying on native vegetation for livestock, and supplementing their diet with game and fish. By the 1800s, forests had given way to larger clearings and abundant wheat fields, with horses pulling wooden plows while farmers used hoes and sickles and separated grain from straw by flailing it or letting livestock trample it; later, scythes and cradle scythes eased some of the cutting labor. In the 1840s, the steel plow, grain drill, mowing machine, and reaper increased the use of horse power and improved productivity, and by the late 1800s self-binding harvesters cut grain into sheaves that were hauled to threshers, where belts and pulleys from steam-driven tractors separated grain from straw. On dairy farms, where most milk was churned into butter, the cream separator improved quality. In the 1900s, internal combustion engines transformed agriculture as tractors gradually replaced horses and mules for plowing, harrowing, cultivating, planting, drilling small grains, mowing and raking grass, loading hay, digging potatoes, harvesting corn, hauling crops, and pulling wagons, while better rural roads allowed motorized trucks to move produce faster than horse-drawn wagons. By the mid-20th century, electricity had reached almost every farm, enabling electric pumps, milking machines, and larger dairy, poultry, and swine operations, and the number of work horses fell from 4,000 in 1935 to 400 by 1954.