Manhattan Project
Nation(s) Involved: United States, United Kingdom, and Canada
Time Period: 1942 to 1946
The infamous Manhattan Project was a closely guarded secret by the United States for many years. They experimented with SEVERAL types of bombs in order to develop the ultimate atomic bomb we know today. Several notable scientists of the day were involved, including Albert Einstein. This was also a joint project between the United States, Canada, and United Kingdom. Thus, we saw scientists from these nations plus others from allied countries or those that escaped oppressive regimes.
The goal might have been to create nuclear weapons, but along the way, they were also able to discover many other things that would not work for this but could for other things. On top of that, they managed to develop weapons that could be used on proper aircraft or those that could be dropped from one. Those might be bombs too, but not always the atomic bomb. Of course, they were doing tests on a lot of dangerous chemicals. Some were exposed to them and died from them or sustained horrible wounds. This project was not held secret for so long due to the bomb but what it took to make it.