For nearly two centuries, through vast upheavals and enormous change, railroads have remained crucial to North American transportation. And always setting the pace have been the mighty American locomotives in all their ever-evolving forms. This collection traces the development of steam, electric, and diesel locomotives from the early nineteenth century right up to the present. More than 250 photographs are accompanied by detailed captions identifying the locomotives and explaining their roles in the history of American motive power. Together, the photographs depict well over 75 locomotive types and reflect the grand geographic and technological breadth of North American railroading.