In the years following the Great Chicago Fire, Chicago was the fastest growing city in the world. With new skyscrapers, huge department stores, and endless strings of streetcars plying every inch of pavement in the business district, city officials realized a new form of transportation was needed to transport Chicagoans safely and efficiently well into the next century. The answer was the construction of Chicago’s elevated transit system, the “L.” Journalist Tom Schaffner traces the history of the L system, describes how it grew, and recounts some of the innovations the system has employed during its long history of serving Chicago area residents and visitors.