The Manhattan Project, the United States Army's program to develop and deploy nuclear weapons in World War II, was a pivotal event in human history. While thousands of articles and books have been published on various aspects of the Project, this is the first comprehensive single-volume history prepared by a specialist for curious readers without a scientific background. The author presents a wide-ranging survey that not only tells the story of how the project was organized and carried out, but also introduces the leading personalities involved and gives qualitative but accurate descriptions of the underlying science and the engineering challenges. The technical points are illustrated by reader-friendly graphics.