The Harmony Route was an interurban electric railway which operated from Pittsburgh to terminals in Butler and New Castle. Along the way this line passed through the North Hills suburban communities including Ross, McCandless, Marshall, Bradford Woods and Cranberry. At Evans City the line split into its two branches with the western branch passing through Zelienople and Ellwood City on its way to New Castle. In 1914, the branch into Ellwood City was extended across the new bridge at Koppel and then south to the lower end of Beaver Falls.

As a rule, early interurban cars were essentially self-propelled railroad coaches with all the wooden construction and ornamentation. Car 115 featured ornate interior decoration, plush seating and a lavatory, for the ultimate in regional intercity travel. There were, however, too few passengers to appreciate this luxury, and the company was economically compelled to abandon its electric operations in 1931.

A close cousin to the Harmony Route was the Short Line, a separate interurban line which reached Butler on a route that passed through Valencia and Mars. This line was bankrupted in the mid-teens and ultimately bought by the more profitible Harmony Route. In 1931, when both lines passed out of existence, the bus company which replaced them operated under the name Harmony Shortline. It is this fact that has for many years prompted some to use this name to refer to all electric railways in the North Hills.

After operations quit, a motorman named Clark purchased the car and had it taken to a plot along State Route 88 (now 65) between Ellwood City and New Castle, where it became a roadside diner. Fifty-five years later, the car was extracted from what had become a much larger restaurant and brought to the Pennsylvania Trolley Museum. As is the case with a number of the Museum’s cars, 115 is the only surviving example from its original owner.