When Cumberland County, PA was first divided into smaller townships and boroughs, Dickinson Township included Cooke and Penn and was then the largest township in the county. By a decree of the Court of Quarter Sessions of this County made April 17, 1785, Dickinson Township was founded. There is no survey on record of the township as it was then constituted, nor does the decree of the court or the petition define its boundaries clearly. It seems certain, however, that it extended from South Middleton on the East to Newton on the West and from the "great road" leading from Harrisburg, PA to Chambersburg, PA (the present Ritner Highway) on the north to Adams County on the South.
Originally the settlers were mainly Scotch Irish, farmers who tilled the rich and fertile soil. The South mountains were covered with forests, two large creeks flowed through the are on their way to the Susquehanna. Mountain Creek, a small stream rising in the South mountains, finds it way through Mt Holly Springs Gap to join the Yellow Breeches Creek West of Boiling Springs. Yellow Breeches Creek begins in Newtown township and flows through Penn and Dickinson Townships on the North side of the mountain, small streams along the way increase its size.
Penn Township was formed from the western portion of Dickinson Township by a decree of the court on October 23, 1860 and included Cook Township until it was formed from the southern part of Penn on June 18, 1872.
The "Historical Sketches of Dickinson Township", published to honor the 200th Anniversary of Dickinson Township, is available for purchase at the Dickinson Township Municipal Building for $22.50 each.