In 1932, less than fifteen years after proving itself a world power in the Great War, the United States could muster its entire active duty army in Chicago's Soldier Field with room to spare. And yet, within months of the December 1941 attack on Pearl Harbor, the United States had once again emerged as the mightiest--and best armed--fighting force in the world. However remarkable it seems, this unprecedented turnaround was not the miracle many have...