The Ligonier Valley Railroad was incorporated in 1852 and was a narrow-gauge line; its early primary purpose was to provide passenger service to and from Idlewild Park near Ligonier. The line formally opened in 1877 after money and ownership issues delayed construction and such. In the later years of the nineteenth century, the line was converted to standard gauge (with a small part of the line by the Standard Steel Works in Latrobe being dual-gauge), and the LGV operated both freight and passenger service until August 31, 1952. It was then when the line ceased operation for good; the following day, the Pennsylvania Railroad took ownership of the first three miles of the line (from Latrobe until Kingston), with the other eight miles of the line (from Kingston to Ligonier) being abandoned. The PRR (and later, Penn Central, CONRAIL, and Norfolk Southern) used the three-mile spur to serve industries such as Timken Steel and Vulcan Mold in Latrobe; as of recently, though, it has been used as storage for MOW equipment.
Norfolk Southern, in particular, has expressed interest in abandoned the remainder of the line; the Latrobe Parks and Recreation Committee, however, has recently stepped in to try and convert the line to a rail trail.
Thanks to Alix Kunkle for contributing information about this route.