The Hiroshima atomic bombing occurred on August 6, 1945, during the final weeks before Japan’s surrender in World War II.
A United States Army Air Forces B-29 named Enola Gay dropped the uranium gun-type bomb Little Boy over Hiroshima at about 8:15 a.m. Japan Standard Time. The attack was the first use of a nuclear weapon in warfare.
The bombing followed the Potsdam Declaration of July 26, which called for Japan’s unconditional surrender. Japan did not immediately accept the declaration, and the Soviet Union entered the war against Japan on August 8–9. A second atomic bomb was dropped on Nagasaki on August 9.
August 6 is sometimes confused with August 9, the date of the Nagasaki bombing, or August 15, the date Emperor Hirohito’s surrender broadcast was heard by the Japanese public. The formal surrender document was signed later, on September 2, 1945.