Penn Township was established on October 23, 1860 from Upper Dickinson Township. It is bordered by Dickinson, Cooke, South Newton, and West Pennsboro Townships. In addition to farming, which has always been the heart of the township, the early residents operated industries such as mills, furnaces, and tanneries. There were inns, taverns, stores, churches, and schools. In addition, there were three train stations located at Hays Grove, Longsdorf Station, and Huntsdale. There are eight villages in the township: Cumminstown, Centerville, Hockersville, Hays Grove, Irishtown, South Fairview, Cobblersville, and Huntsdale, but no incorporated towns.
Penn Township is located midway between Carlisle and Shippensburg. Routes 81 and 11 traverse the township from east to west and Route 233 from north to south. The town of Newville is to the north, and Pine Grove Furnace State Park and Laurel and Fuller Lakes is just a few minutes to the south through the lovely Michaux State Forest on South Mountain.