The armored divisions were the shock force of the US Army's combat formations during the fighting in Northwest Europe in the final year of the war. Of the 16 such divisions formed during the war, all but one served in the European Theater of Operations. This book examines the organizational structure, operational doctrine and combat mission of these divisions from D-Day onwards, describing how doctrines and tactics were changed as the divisions were forced to adapt to the battlefield realities of combat against an experienced foe. The lessons drawn by the armored divisions from the bitter fighting in Northwest Europe from 1944 to 1945 strongly shaped postwar US Army doctrine.