They dropped the plutonium bomb of August 9, 1945, 3 days after they bombed Hiroshima with the uranium bomb. The bomb was used to destroy Kokura, Japan, but because of the planes were low on fuel and the weather was cloudy, they would either have to drop it in the ocean and not detonate it or detonate on Nagasaki. The USA decided to dropped it and detonate it on Nagasaki, Japan. The USA made the bomb because it was was more powerful than the uranium bomb, but due to changes in location and other variables, they detonated it early causing less devastating effects than the uranium bomb.
Major Charles Sweeney's bomber, Bockscar, dropped and detonated the plutonium bomb about 1800 feet above Nagasaki.
Major Charles Sweeney's bomber, Bockscar, dropped and detonated the plutonium bomb about 1800 feet above Nagasaki.