U.S. Officials Observer Damage From Atomic Bombs Dropped on Hiroshima and Nagasaki Ca. 1945
In August 1945, the United States dropped atomic bombs on Hiroshima and Nagasaki, two large cities in Japan. The immense power of the weapon convinced Japan to surrender unconditionally and prevented a U.S. invasion of the mainland. However, many historians have questioned President Harry S. Truman's decision to order the attack without first warning the Japanese of the bomb's power.