Little Boy was the atomic bomb dropped on Hiroshima before Japan’s surrender in World War II.
The United States dropped Little Boy over Hiroshima on August 6, 1945. It was a uranium-235 gun-type nuclear weapon carried by the B-29 bomber Enola Gay. The explosion caused catastrophic destruction and loss of life across the city.
Little Boy is often confused with Fat Man, the plutonium implosion weapon dropped on Nagasaki three days later. Gadget was the name of the first nuclear device tested at Trinity in New Mexico, while Thin Man was an earlier design concept that was abandoned.
The Hiroshima bombing was followed by the Soviet Union’s declaration of war on Japan and invasion of Japanese-held territory, then by the Nagasaki bombing. Historians continue to debate how these events individually and collectively influenced Japan’s decision to accept the Allied surrender terms.