Reading is perhaps the essential practice of modern civilization. For centuries, it has been seen as key to both personal fulfillment and social progress, and millions today depend on it to participate fully in our society. Yet, at its heart, reading is a surprisingly elusive practice. This book tells for the first time the story of how American scientists and others have sought to understand reading, and, by understanding it, to improve how people do it. Starting around 1900, researchers--convinced of the urgent need to comprehend a practice central to industrial democracy--began to devise instruments and experiments to investigate what happened to people when they read. They traced how a good reader's eyes moved across a page of printed characters, and they asked how their mind apprehended meanings as they did so. In schools across the country, millions of Americans learned to read through the application of this science of reading. At the same time, workers fanned out across the land to extend the science of reading into the social realm, mapping the very geography of information for the first time. Their pioneering efforts revealed that the nation's most pressing problems were rooted in drastic informational inequities, between North and South, city and country, and white and Black--and they suggested ways to tackle those problems. This book explains both how the science of reading shaped our age and why, with so-called reading wars still plaguing schools across the nation, it remains bitterly contested.