Between 1917 and 1945, the U.S. Army's concepts of armored warfare grew from a platform focus and a narrowly defined mission into a broad capability. Mobility, Shock, and Firepower: The Emergence of the U.S. Army's Armor Branch, 1917-1945 captures the multifaceted development of the Armored Force from its beginnings in World War I to a mature, operational status at the close of World War II. Through analysis of the Armor Branch's early years, the book provides an excellent case study in force transformation. The development of new armor doctrines and organizations to exploit emerging technologies, concepts, and missions is the heart of this work. How that transition was accomplished during the brief space of about twenty years-the accepted duration of a single generation-is a story worthy of careful examination as our Army gropes with managing similar transformations today.