Book excerpt: A team of leading American military historians here investigate the factors that shaped the United States Army in the nineteenth century. Throwing new light on its history, this deeply researched book explores a mulitplicity of themes. These include the social structure, command system and relationship with civil power which are all important in assessing its efficiency and behaviour in war; and the way the army is depicted in military literature and cinema which affects its social portrait. Deliberately exploring neglected themes, this key work includes discussion on: * the roles of the many volunteer colonels in the Mexican War, 1846-48 * Robert Wettemann and the alleged 'isolation' of the US Army in the nineteenth century * John Ford's famous 'cavalry trilogy' of motion pictures. Containing so much food for thought, for students of US history and military history this is an entertaining as well as instructional book.