How many atomic bombs did the United States build in World War II?

Three, namely "Skinny Man", "Fat Man" and "Little Boy", of which the Slim Man was an experimental bomb, while the Fat Man and the Little Boy were dropped on Nagasaki and Hiroshima, Japan respectively

■Skinny

The code name for one of the world's first three atomic bombs developed by the United States. It was tested in the desert near Alamogordo, New Mexico, on July 16, 1945. .

■Little Boy

The code name of one of the world's first three atomic bombs developed by the United States, which was used on Hiroshima, Japan on August 6, 1945. This is a nuclear bomb made of uranium, with a length of 2.5 meters, a maximum outer diameter of 0.71 meters, a weight of 4.1 tons, and a power equivalent to less than 20,000 tons of TNT. Because it was much smaller than "Fat Man", another nuclear bomb at the time, it was codenamed "Little Boy".

■Fat Man

The code name of one of the world's first three atomic bombs developed by the United States and used on Nagasaki, Japan on August 9, 1945. This is an atomic bomb made of plutonium, with a length of about 3.3 meters, a maximum outer diameter of 1.5 meters, a weight of about 4.5 tons, and a power equivalent to 20,000 tons of TNT. Because of its large size, it was nicknamed "Fat Man".