Colonials, continentals, and federals : the origins of American military professionalism -- Tactical expertise and the U.S. Army before the war with Mexico -- The old army's vindication : the Mexican war -- Tactical continuity in the decade before the Civil War -- The beginning of the end : the old army on the precipice -- War in earnest : the first battles of 1861 -- The Peninsula : Lee and McClellan leave their legacies -- Morale, cohesion, and competence from Second Bull Run to Missionary Ridge -- Decisions east and west : the end of the Civil War.