In the literature of World War II, the relative military effectiveness of the United States and German forces was a lively debate until the last decade of the 20th century, when a handful of American historians established the now familiar narrative of how the U.S. achieved supremacy. Yet much of this view is based on misconceptions and the exclusion of key considerations. Drawing on a range of sources and new evidence, the author presents a nuanced examination of the consensus that the U.S. armed forces--outclassed at first but rising to the challenge--triumphed against and enemy possessing myriad advantages.