That portion of York County, which is now Franklin Township, was probably first settled about 1760. Franklin Township was formed in 1809 from a part of Monaghan Township. The petition for the new Township was signed with names such as: Logan, Prosser, Gatticart, Anderson, Elcock, Mumper, Smyser, Lau, Klugh, and Knisley. There was a considerable difference of opinion as to what name should be given. It was proposed to call it Dill Township, but this did not receive sufficient support and the new district was named Franklin. By 1810 it had 175 taxable inhabitants and a property valuation of $ 97,521. In that same year, the following businesses were in Franklin Township: 3 inn-keepers, 2 physicians, 1 tannery, 11 weavers, 4 sawmills, 4 distilleries and 3 gristmills. Franklin Township was reduced to its present size in 1831, when part of it was taken to form part of Carroll Township.
In what was to become Franklin Township, the Germans predominated. The Heiges, Ginters, Mumpers, Hoffmans, Leases, Princes, and Millers were among the first settlers that included the Quakers. There were also many Scotch-Irish and German pioneers. Early pioneer families in Franklin Township had to contend with both Indian raids and the menace of wild animals that lived in the nearby South Mountains. As late as 1780, it was reported that the Indians drove several men who lived along the mountains from their land.
Various areas of the Township are "labeled" with various local names, such as - Union Church, Slabtown, Coffeetown, Clear Springs, Stonehead, etc.