History for the day: 1945: Atom bomb successfully tested

History.com has this for 16 July:

On 16 July 1945, at 05:29:45, the Manhattan Project came to an explosive end as the first atom bomb was successfully tested (photo) in Alamogordo, New Mexico.
Plans for the creation of a uranium bomb by the Allies were established as early as 1939, when Italian emigre physicist Enrico Fermi met with Navy Department officials at Columbia University to discuss the use of fissionable materials for military purposes. That same year, Albert Einstein wrote to then-President Franklin Roosevelt supporting the theory that an uncontrolled nuclear chain reaction had great potential as a basis for a weapon of mass destruction. In February of 1940, the Federal government granted a total of $6,000 for research. But, in early 1942, with the United States now at war with the Axis powers, and fear mounting that Germany was working on its own uranium bomb, the War Department took a more active interest, and limits on resources for the project were removed.
Brigadier-General Leslie R. Groves, himself an engineer, was now in complete charge of a project to assemble the greatest minds in science and discover how to harness the power of the atom as a means of bringing the war to a decisive end. The Manhattan Project (so-called because of where the research began) would wind its way through many locations during the early period of theoretical exploration, most importantly, the University of Chicago, where Enrico Fermi successfully set off the first fission chain reaction. But the Manhattan Project took its final form in the desert of New Mexico, where, in 1943, Robert J. Oppenheimer began directing Project Y at a laboratory at Los Alamos, along with such scientists as Hans Bethe, Edward Teller, and Enrico Fermi. Here theory and practice came together, as the problems of achieving critical mass and the construction of a deliverable bomb were worked out.
Finally, on the morning of 16 July 1945, in the New Mexico desert, a hundred and twenty miles south of Santa Fe, New Mexico, the first atomic bomb was detonated. The scientists and a few dignitaries had removed themselves ten thousand yards away to observe as the first mushroom cloud of searing light stretched forty thousand feet into the air and generated the destructive power of fifteen to twenty thousand tons of TNT. The tower on which the bomb sat when detonated was vaporized.
The question now became on whom was the bomb to be dropped? Germany was the original target, but the Germans had already surrendered. The only belligerent remaining was Japan.

A footnote: The original $6,000 budget for the Manhattan Project finally ballooned to a total cost of two billion dollars.

Rico says we'd have been better off if we'd never invented them... (The Japanese, especially.)