In 1939, Albert Einstein wrote to FDR supporting the idea that an uncontrolled nuclear chain reaction had potential as a weapon. Enrico Fermi had ideas how to do this. In February 1940, the federal government set aside $6,000 for research on it.
In early 1942, the United States was now at war with the Axis. Germany was believed to be working on a uranium bomb. The War Department took an interest in the U.S. project and limits on resources were removed. Brigadier-General Leslie R. Groves, an engineer, was put in charge of the research effort, which was located initially in Manhattan and was therefore called the Manhattan Project.
The Project succeeded in the desert of New Mexico. In 1943, Robert J. Oppenheimer began directing Project Y at a laboratory at Los Alamos, along with Hans Bethe and Edward Teller, as well as Fermi. My former headmaster, Rev. Leo van Winkle, a Yale Ph.D. in Physics, was working on the project.
The first atomic bomb was detonated as scientist observers watched from six miles away. The first mushroom cloud stretched up 40,000 feet. The explosion began with intense light and ended with had the destructive power of perhaps 20,000 tons of TNT, followed by radioactive fallout. The tower holding the bomb was vaporized.
Germany was the original target, but they had surrendered. The only belligerent remaining was Japan. Henry Kissinger said once:
"The greatest danger of war seems to me not to lie in the deliberate actions of wicked men, but in the inability of harassed men to manage events that have run away with them."