During the first fifty years of the twentieth century, the United States saw two world wars, a devastating economic depression, and more social, political, and economic changes than in any other five-decade period before. Frederick Lewis Allen, former editor of Harper's Magazine, recounts these years—spanning World War I, the Progressive Era, the Great Depression, World War II, and the early Cold War—in vivid detail, from the fashions and customs of the times to major events that changed the course of history. Politically, the United States grew into its own as a global superpower during these years, even as domestic developments altered the everyday lives of its citizens. The introduction of the automobile, mass production, and organized labor changed the way Americans lived and worked, while innovations like penicillin and government regulation of food safety contributed to an increase in average life expectancy from forty-nine years in 1900 to sixty-eight years in 1950. With the development of a strong, centralized government, a thriving middle class, and widespread economic prosperity, the nation emerged from the Second World War transformed in virtually every way. Richly informative, The Big Change is an indispensable volume charting the many changes that ushered in our contemporary age.