The very first atomic bomb was exploded in a test in the New Mexico desert on July 16, 1945. If you'd like to look up more information about it, you can look up the codename "Trinity".
USSR
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When the Soviet Union exploded an atomic bomb, the US response was to increase its own arsenal and its own testing of nuclear weapons.
The first exploded over Heroshima, the second over Nagasaki.
It was in 1949 that the Soviet Union exploded an atomic bomb, and the communists gained control of China. Both of these events were worrisome to the U.S.
8.15 am
fartland
The first atomic bomb used against mankind exploded at 8.15 over Hiroshima.
The first atomic bomb, produced by the ultrasecret Manhattan Project at a cost of $2 billion, exploded in the desert near Alamogordo, New Mexico, on July 16, 1945. The results were recorded and Truman was sure that such force will end Japan's capacity to make war.
See website: Atomic bombings of Hiroshima and Nagasaki. people living there died.
It was a plutonium implosion type. So it was an atomic bomb.