This was the basis for the atomic bomb. Throughout this research paper, I will trace the history of the atomic bomb. In addition, who was involved and why, what happened in this event, and explain the impact that it had on the world. After Einstein predicted, that mass could be converted into energy. This was confirmed experimentally by John D. Cockcroft and Ernest Walton. “Physicists from 1939 onward conducted much research to find answers to questions as how many neutrons were emitted in each fission and which elements would not capture the neutrons but would moderate or reduce the velocity” (Grolier Multimedia Encyclopedia The Atomic Bomb Mar.99 CD-ROM NP) and other questions of that nature. Frightened by the possibility that the Germans may produce an atomic bomb, physicists Leo Szilard, Eugene Wigner, and Edward Teller consulted Einstein to address a letter to Franklin Roosevelt. Motivated by the letter, in 1939 Roosevelt commanded an American effort to obtain atomic weaponry before the Germans. With an increasing threat from Germany, President Roosevelt needed to take an aggressive stance. He was in a position of nuclear threat. F.D.R needed to do something, and do something very fast. This is why the president called to order the “Manhattan Project.” Nothing happened until Vannevar Bush, coordinator of scientific activities for the war, took charge. The program was called the Manhattan Project. It came under United States Army control in 1942. The Manhattan Project is a code name for the United States efforts to complete the separation of uranium-235 out of the uranium238. The development of these compounds resulted in the impact of nuclear energy in the 20th century. President Roosevelt would later spend 2 billion dollars on this project. His goal was to ensure the safety of his nation and be a leader in the use of nuclear energy. The men who coordinated the Manhattan Project were an important part of t...