The History of the Manhattan Project

Leo Szilard was one of the earliest figures in nuclear science. In 1933, he read a speech by Ernest Rutherford that declared splitting an atom to be impossible. He disagreed with Rutherford's conclusion and went for a walk to muse over the topic. As he waited for a traffic light to change,. Szilard had a flash of inspiration and envisioned a nuclear chain reaction. The Manhattan Project officially began on September 4, 1945.