On the 2nd of August 1939, scientists wrote to President Roosevelt telling him of efforts in Germany to purify Uranium 235, which could be used to make an atomic bomb. Roosevelt then set up an "Uranium Committee" to research into an atom bomb. Once the United States entered the war, this situation changed dramatically. Scientists working in Britain had discovered how to control an atomic explosion. This was a very important step to making the bomb, and the British gave their knowledge to the Americans. In December 1942, President Roosevelt began the Manhattan Project.
The Manhattan Project was a group of top nuclear scientists who were to find out how to make an atomic bomb. This group of scientists was under the command of General Leslie Groves, and Robert Oppenheimer. The project took place in many places across the United States, but mainly in Los Alamos, New Mexico. Los Alamos was a small town consisting of a school and a few homes. This was bought up by the U.S. government, and made into a secret city that would eventually house 6,000 people. This was a very secretive time and the scientists didn't enjoy their surroundings very much. .
Making the bomb proved to be harder than originally thought. The Germans and Japanese came close to making it, but did not have resources. President Roosevelt gave the project limitless amounts of money, and kept the project secret from Congress and the public. In the end he spent more than $US2,000,000,000 on the project. Many factories were built to make the uranium and plutonium needed for the bomb. At the high point of the project, more than 200,000 people were employed in the project. Many of these people had no idea what they were making because of the secrecy of the project.
In 1944, General Groves told President Roosevelt with confidence that the first atom bombs would be ready in the summer of 1945. By the time the bombs were ready, the U.S knew that there was no longer a race to make the first bomb, but there was a race to get the bomb made before the end of the war because both Germany and Japan were facing defeat.
