Running along current day Cheyney Road, PA 112 began at an intersection with U.S. Route 1 (US 1) in Markham, headed northward, and terminated at an intersection with PA 926 in the community of Tanguy.

The route remained intact for thirteen years, when, in 1941, the highway was extended southward to US 322 south of Markham.

After that intersection, PA 112 turned to the northeast, passing through Markham before leaving the community.

North of the community of Cheyney, Route 112 crossed the county line, passing the Cheyney University of Pennsylvania before the terminus at an intersection with Pennsylvania Route 926 in the Chester County community of Tanguy.

[6] Although they made the adjustment, PA 112 ended up becoming one of the many routes decommissioned in 1946, when the commonwealth of Pennsylvania removed several hundred miles from their system.