The
atomic bomb was the name used in the 1950s for the first of what are now called
nuclear weapons. It was originally developed out of fear that the Germans were also working on such a weapon (as in fact they were, although they did not get very far with their project.) This development represented the peak of
technology in World War II.
The secret wartime project that developed the bomb was called by the code name the Manhattan project. It had nothing to do with Manhattan. Much the development took place at Los Alamos, New Mexico. The town, laboratories, production and test facilities built there for the Manhattan Project became what is today the Los Alamos National Laboratory.
The United States dropped two atomic bombs named
Little Boy and
Fat Man on the Japanese cities of
Hiroshima and
Nagasaki, bringing the war between the US and Japan to a swift and decisive end.