"Little Boy" was the atomic bomb dropped on Hiroshima, Japan, by the American bomber plane Boeing B29 Superfortress Enola Gay plane.
On August 6, 1945 American President Harry S. Truman ordered the bombing of Hiroshima, Japan to subdue Japan into surrender and a speedy end to the war. America remains the only country to have ever used an atomic bomb against an enemy. It resulted in the deaths of tens of thousands of civilians. Three days later Nagasaki, another city in Japan was atomic-bombed as well.