A Command Post at War is a unique story about an American field army headquarters and its organization and role in World War II, a perspective that has received little attention by historians until now. David W. Hogan Jr. examines the First Army headquarters's response to the test of army-level command during the period from its activation in October 1943 to V-E Day in May 1945. Focusing on the operational level, the level between the grand strategy of nations and theaters and the tactical combat of corps and smaller units, Hogan analyzes the operations, intelligence, logistical, and administrative functions of the headquarters; the procedures evolved to carry out those functions; and the impact of the personalities and styles of the commander and staff chiefs on the organization. Hogan's volume shows the army headquarters of World War II as a complicated organization with functions ranging from immediate supervision of tactical operations to long-range operational planning and the sustained support of frontline units. It is a valuable case study for military professionals at all levels.