It runs 21.7 miles (34.9 km) from a junction with the SEPTA Main Line just north of Jenkintown–Wyncote to West Trenton, just across the Delaware River.

It was originally built in 1876 as part of the much longer New York Branch, which continued north to Bound Brook, New Jersey.

The electrified section between Jenkin and West Trenton was designated the Neshaminy Line and is now owned by SEPTA.

Growing congestion and the need to implement positive train control (PTC) led to SEPTA and CSX undertaking the West Trenton Separation Project in 2015.

This project built a new third track between Woodbourne and Yardley, fully separating the Neshaminy Line and the Trenton Subdivision.