If you ever wondered exactly how WWII was ended, look no further.
The Manhattan Project was the code name for the US program to develop nuclear weaponry during WWII. Specifically, this project focused on the creation of the atom bomb, which is a highly powerful and radioactive explosive that is charged by nuclear fission, or the chemical act of splitting an atom. The physical reaction to this creates a massive amount of energy that expels itself outward with additional harmful radiation.
The creation of this bomb engaged some of the most important scientific minds of the time. Most of the development was done in Los Alamos, New Mexico, and not New York City, despite the contrary name.
The Manhattan Project was started because the U.S. (and its allies) caught wind of a rumor that German scientists were in the process of developing a nuclear weapon that Adolf Hitler had planned to use on some of the most powerful allied nations.
The following year after the U.S. founded the program, America joined WWII on the ground, only after Japanese forces attacked American soil at Pearl Harbor.
The allied forces destroyed the Nazi military before America had even completed the atom bomb. But, Japanese forces were still waging war with the surrounding areas. So, the U.S. decided to use the atomic bomb on Japan. In 1945, the U.S. dropped two nuclear warheads on Japan. One on Hiroshima, and the other on Nagasaki, killing over 100,000 people in total and ruining the lives of millions.