Book excerpt: A major period of westward expansion took place in the United States during the first half of the 19th century. Fur trading, the coast-to-coast railroad, the California gold rush and the removal of Native American tribes both facilitated and encouraged America's "manifest destiny" to become a transcontinental nation. The task of protecting the settlers from the tribes that inhabited the Great Plains fell to the US Army, and to do this an extensive network of permanent forts was created via construction and acquisition. This title examines why the forts were built, as well as their design, defensive features and the role they played in the settlement of the American West. The daily lives of the garrison soldiers and fort inhabitants are also covered, together with the fighting witnessed at key sites.