With the violent separation between the United States and Britain which began in 1776, the new 'Americans' set off to fulfill their manifest destiny and rule their new land from coast to coast.

As they pushed westward, they came into conflict with both natives and other European settlers, and began to build fortresses to defend their newly claimed land. This book charts the development and variation of the fortresses of the American Frontier, covering both American defenses and those of the Spanish in the west. It also examines the little-known forts of early Russian settlers on the Pacific coast.

Until his retirement in 2007, Ron Field was Head of History at the Cotswold School in Bourton-on-the-Water. He was awarded a Fulbright Scholarship in 1982 and taught history at Piedmont High School in California from 1982 to 1983. He was associate editor of the Confederate Historical Society of Great Britain, from 1983 to 1992. He is an internationally acknowledged expert on US military history, and was elected a Fellow of the Company of Military Historians, based in Washington, DC, in 2005.

Adam Hook studied graphic design, and began his work as an illustrator in 1983. He specializes in detailed historical reconstructions, and has illustrated Osprey titles on the Aztecs, the Greeks, several 19th-century American subjects, and a number of books in the Fortress series. His work features in exhibitions and publications throughout the world.