In order to beat the German Nazis in creating the first atomic bomb, the Manhattan Project was created and funded by the US government. The invasion of Poland had officially sparked the start of WWII. After the invasion, Germany's leader, Adolf Hitler, had announced to Great Britain that a weapon was going to be created in "which there is no defense." British intelligence got right onto that statement. After analyzing, they had four conclusions. They were: " 1) Hitler was bluffing 2) Nazis had developed a poison gas 3) Hitler was referring to the German Air Force, the Luftwaffe 4) the Germans had developed the atomic bomb. After this announcement, red flags immediately went up.
After that Einstein's letter was written; therefore, the Manhattan project was created. The Manhattan Project's sole purpose was to create the first ever atomic bomb. The Manhattan Project was greatly assisted by Great Britain and Canada (Wikipedia). This project also "ranks as one of the largest industrial and scientific effort by the history of the world." It costs more than $2 billion dollars during 1945 and also gave jobs to more than 175, 000 workers. Also all this work was done in absolute secrecy. The project started in 1942 and ended in 1946.
Then the project had became the Atomic Energy Commission. The project was split into 3 sections. The 3 sections included, Los Alamos, New Mexico; Oak Ridge, Tennessee; and Hanford, Washington. This whole project was supervised under General Leslie R. Groves, but it was scientifically supervised under Robert J.
Oppenheimer. After the project, a total of four atomic bombs were developed. But only three were ever used.