It was the thoughts of Albert Einstein that led to the creation of the atomic bomb. The way the atomic bomb works is by fission.
Fission is the process of splitting atoms to create energy.
Fission was discovered in 1938. The material they split to create the energy is called uranium. There was a great rush to complete the atom bomb because of the threat other countries would have if they were the first to complete it. The Manhattan Project was a project to speed up the creation of the atom bomb. The Manhattan Project included a work force of over one hundred thousand workers and took over three years to complete.