The William Penn Highway was a major route through the Appalachian Mountains between Philadelphia and Pittsburgh throughout the 20th century. Established in 1916, a decade prior to the federal highway system, the road succeeded the former Northern Turnpike, with much of it following the course of the Pennsylvania Railroad through the Juniata River Valley. The highway also followed the former path of the Allegheny Portage Railroad in climbing the long grade of the Allegheny Ridge. In 1926, US Route 22 was established to follow the highway's course, extending it eastward to Newark, New Jersey, and westward to Cincinnati, Ohio, where it remains well traveled today. This book shows many of the highway's scenic and historic sites.