What is an Atomic Bomb and what was it used for?
"An atomic bomb is a bomb that gets its destructive power from the rapid release of nuclear energy by fission of heavy atomic nuclei, causing damage through heat, blast, and radioactivity." (The Decision to Drop the Bomb.)
The U.S. created the first atomic bomb in fear that Germany was going to create and use one against the U.S. The U.S. used the atom bombs first as a threat and then for total destruction to end the war.