Harry S. Truman significant event atomic bombings of Hiroshima and Nagasaki
Dropping atomic bombs on Japan
Truman benefited from a honeymoon period from the success in defeating Nazi Germany in Europe and the nation celebrated V-E Day on May 8, 1945, his 61st birthday.Although Truman was told briefly on the afternoon of April 12 that he had a new, highly destructive weapon, it was not until April 25 that Secretary of War Henry Stimson told him the details. 
We have discovered the most terrible bomb in the history of the world. It may be the fire destruction prophesied in the Euphrates Valley Era, after Noah and his fabulous Ark.
Truman journeyed to Berlin for the Potsdam Conference with Joseph Stalin and the British leader Winston Churchill. He was there when he learned the Trinity test—the first atomic bomb—on July 16 had been successful. He hinted to Stalin that he was about to use a new kind of weapon against the Japanese. Though this was the first time the Soviets had been officially given information about the atomic bomb, Stalin was already aware of the bomb project—having learned about it through atomic espionage long before Truman did.In August, the Japanese government refused surrender demands as specifically outlined in the Potsdam Declaration. With the invasion of Japan imminent, Truman approved the schedule for dropping the two available bombs. Truman always said attacking Japan with atomic bombs saved many lives on both sides; military estimates for the invasion of Japan were that it could take a year and result in 250,000 to 500,000 Allied casualties. Hiroshima was bombed on August 6, and Nagasaki three days later, leaving 105,000 dead. The Soviet Union declared war on Japan on August 9 and invaded Manchuria. Japan agreed to surrender the following day.
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