Nuclear fission the Manhattan Project during World War II (September 1, 1939 – September 2, 1945) carried out most of the early scientific work on fission chain reactions, culminating in the three events involving fission bombs that occurred during the war. The first fission bomb, codenamed "The Gadget", was detonated during the Trinity Test in the desert of New Mexico on July 16, 1945. Two other fission bombs, codenamed "Little Boy" and "Fat Man", were used in combat against the Japanese cities of Hiroshima and Nagasaki in on August 6 and 9, 1945 respectively. Even the first fission bombs were thousands of
Anti-nuclear movement in the United States surveys showed rising public uneasiness about the nuclear arms race—especially atmospheric nuclear weapons tests that sent radioactive fallout around the globe. In 1962, Linus Pauling won the Nobel Peace Prize for his work to stop the atmospheric testing of nuclear weapons, and the "Ban the Bomb" movement spread throughout the United States. Between 1945 and 1992, the United States maintained a program of vigorous nuclear weapons testing. A total of 1,054 nuclear tests and two nuclear attacks were conducted, with over 900 of them at the Nevada Test Site, and ten on miscellaneous sites in the United States (Alaska, Colorado,