No symbol of progress in our century is more galvanizing than electricity—electric power and the technology it has spawned. The "invisible world" of electric energy that was emerging at the turn of the century is one we take for granted, but its influence on the growth and quality of city life was, and remains, profound. Using Chicago as a test case, Harold L. Platt investigates the emergence of an urban-based, energy-intensive society over the course of half a century in this first book-length history of energy use in the city.