S-1 Uranium Committee - World War II Begins

World War II Begins

World War II began with the German invasion of Poland on September 1, 1939, prompting Albert Einstein and Leó Szilárd to complete the letter to U.S. President Franklin Delano Roosevelt they had been working on over the summer. This letter was signed by Einstein on August 2, and it was hand-delivered to Roosevelt by the economist Alexander Sachs on October 11, 1939. The letter advised Roosevelt of the existence of the German nuclear energy project and warned that it was likely the Germans were working on an atomic bomb using uranium, and that the U.S. should be concerned about locating sources of uranium and researching nuclear weapon technology. At this time the U.S. policy was neutral in the war.

Experiments with the fission of uranium were already going on at universities and research institutes in the United States. Alfred Lee Loomis was supporting Ernest Lawrence at Berkeley Radiation Laboratory and Enrico Fermi at Columbia. Vannevar Bush was also doing similar research at Washington, D.C.-based Carnegie Institution. After the April 29, 1940 spring meeting of the American Physical Society, the New York Times reported that conferees argued "the probability of some scientist blowing up a sizable portion of the earth with a tiny bit of uranium."