Entire libraries could be written on the Pennsylvania Railroad ranging from its history to the different businesses it owned, far too much to cover here which is a mere brief history of the railroad. The Pennsy was an institution to the City of Philadelphia and State of Pennsylvania. For over 100 years, the keystone represented the PRR as much as it did the State of Pennsylvania itself. For history's sake, you cannot really speak of the Pennsy without also mentioning the New York Central (and vice versa). It is quite amazing how similar both were outside of their operational practices. Both were institutions, two of the largest railroads in the country, and the class of the industry for decades.