The Lenni Lenappe Indians together with the Iroquois were the first known people in the township. Migration to America began around 1700, with Scotch-Irish immigrants settling in the area now known as Weaversville.
The famous "Walking Purchase" occurred in 1737, and alienated the Indians and the white men. Historical monuments are located within the township describing this act as it happened.
But as the German and English settled, built their homes, and began to work the land, relations with the Indians also improved.
Allen Township, as known today, was originally part of Bucks County. Thirty-seven signers, mostly Scotch-Irish, formed a petition to the Court of Quarter Sessions in Newtown, Bucks County, in June 1748, for the creation of a township. The present metes and bounds were established and finally coordinated in 1752 and 1845, respectively. The name is derived from Chief Justice William Allen of Philadelphia who owned the "Allen Tract" of 5000 acres.
During the 1840's, the township and surrounding areas became predominantly occupied by the German settlers who began not only actively tilling the land, but also providing their needed services to the residents. Kreidersville had tailor and shoe shops, machine and woodworking shops, the general store and a post office. A brickyard and a tannery existed in Wernersville. Blacksmiths, gristmills, coach makers, and physicians also were engaged in providing services and products to the township and adjacent areas.