On August 6 and 9, 1945, in the last significant blows of World War II, American B-29 bombers dropped atomic warheads on the Japanese cities of Hiroshima and Nagasaki. Within a week, the Japanese surrendered. The war was over, but the Atomic Age was just beginning. Here, from journalist and historian Michael Blow, is the dramatic story of America's Manhattan Project, which produced the world's first atomic weapons.