The Pennsylvania and the New York Central railroads, introduced in the 1860s and 1880s respectively, were instrumental in establishing Pennsylvania as the nation's largest source of coal. Although the two lines quickly forged a rivalry over the territory, rapid change at the turn of the nineteenth century forced them to adopt new technologies and eventually merge into one company. In Branch Line Empires, take a trip back in time to learn about this legendary relationship in exquisite detail thanks to Michael Bezilla's expertise in the history of technology and railroading.