This book tells the fascinating story of American English, tracing its emergence in the colonial period through to the present day. Written by a leading scholar, and drawing on data from the Linguistic Atlas Project, it explores how and why American English differs from British English, how it has been standardized, and how the USA's global political power has influenced its prominent status around the world. Illustrated with copious examples of language in use, it also surveys the various dialects of American English, including African American English, and explores social and cultural variation between English and other languages spoken in the United States. Each chapter explains the relevant terms and concepts from linguistics, and provides computer-based exercises. The author also introduces the basics of complexity science, showing how complex systems shape development and change in American English. Authoritative yet accessible, it will be essential reading for researchers and students alike.