How and why the US developed the atomic bomb?

Answer 1

At the outset of World War 2 there was great fear in the scientific community that Nazi Germany would be the first to develop nuclear weapons. There was no doubt in the minds of physicists, many of whom were refugees from the Nazis, that Hitler would use an atom bomb if he obtained one. Accordingly the United States, Britain and Canada jointly developed the first atomic weapons in what was called the Manhattan Project.

Below are related links to Wikipedia articles on this subject, which is likely far too complex to answer in this forum. You can also try Googling "Nuclear Weapons," and of course you can and should visit your local library. Your librarian will be more than happy to steer you to dozens of books on this subject, which is truly fascinating and at times simply as mind boggling as a nuclear explosion.

Another Answer: US developed atomic bomb by setting up a scientific committee to study the issue. The British research so impressed the Americans that they convinced Roosevelt to begin a program to build an atomic bomb. The American program to build an atomic bomb was code-named the Manhattan Project. The project's first breakthrough came in 1942, when Szilard and Enrico Fermi, another physicist, built the world's first nuclear reactor at the University of Chicago. Groves organized a team of engineers and scientists to build an atomic bomb at a secret laboratory in Los Alamos, New Mexico.

Answer 2

There were probably two underlying reasons: The Manhattan project takes care of how. Why was more complex, there was a fear that the
Axis was already making an effort to produce atomic weapons and the
Allies would have to counter this potential threat, and there was a certain
knowledge that with enough time, money and effort an atomic weapon
could and would be produced to end World War 2 with the United States
in a preeminite position.

Answer 3

I suggest reading Richard Rhodes' book The Making of the Atomic Bomb.