George C. Marshall once called him "the brains of the army." And yet General Lesley J. McNair (1883-1944), a man so instrumental to America's military preparedness and Army modernization, remains little known today, his papers purportedly lost, destroyed by his wife in her grief at his death in Normandy. This book, the product of an abiding interest and painstaking research, restores the general Army Magazine calls one of "Marshall's forgotten men" to his rightful place in American military history. Because McNair contributed so substantially to America's war preparedness, this first complete account of his extensive and varied career also leads to a reevaluation of U.S. Army effectiveness during WWII. Born halfway between the Civil War and the dawn of the 20th century, Lesley McNair--"Whitey" by his classmates for his blond hair--graduated 11th of 124 in West Point's class of 1904 and rose slowly through the ranks like all officers in the early twentieth century. He was 31 when World War I erupted, 34 and a junior officer when American troops prepared to join the fight. It was during this time, and in the interwar period that followed the end of the First World War, that McNair's considerable influence on Army doctrine and training, equipment development, unit organization, and combined arms fighting methods developed. By looking at the whole of McNair's career--not just his service in WWII as chief of staff, General Headquarters, 1940-1942, and then as commander, Army Ground Forces, 1942-1944--Calhoun reassesses the evolution and extent of that influence during the war, as well as McNair's, and the Army's, wartime performance. This in-depth study tracks the significantly positive impact of McNair's efforts in several critical areas: advanced officer education; modernization, military innovation, and technological development; the field-testing of doctrine; streamlining and pooling of assets for necessary efficiency; arduous and realistic combat training; combined arms tactics; and an increasingly mechanized and mobile force. Because McNair served primarily in staff roles throughout his career and did not command combat formations during WWII, his contribution has never received the attention given to more public--and publicized--military exploits. In its detail and scope, this first full military biography reveals the unique and valuable perspective McNair's generalship offers for the serious student of military history and leadership.