The Gale Encyclopedia of U.S. History consists of a series of 2-volume encyclopedias that provides a broad overview of one particular topic throughout American history, from pre-colonial times until today, with special emphasis placed on how the topic–whether war or government and politics–effects, and is affected by, political, economic, and social change in American and global society. Each set is organized chronologically, by era or event, into 10-15 chapters. Each chapter features an introductory essay on the era or event followed by entries grouped under consistent subheads. Each set consists of approximately 400 entries, including subject entries and biographies; 300-350 images, including maps; a chronology; a glossary; sources for further study; and a general index.