For more than a century, fossil fuels have defned the lives of every American, and few states have contributed more to this bounty than Pennsylvania. The commonwealth’s diverse energy resources have been repeatedly connected to markets and converted into power and commodities. Pennsylvania has been a place where innovators attempted pioneering techniques and developed new technologies. Although its energy history has exerted a signif cant toll on Pennsylvania’s environment and citizens, it has also enabled the state to lead the nation into and through the industrial age. Today, as yet another energy frontier emerges—natural gas mined from shale—investigating ways that various energy forms were developed in Pennsylvania is particularly compelling. Thus, a special issue of the Pennsylvania Magazine of History and Biography on Energy in Pennsylvania is timely.