The first atomic bomb was developed by the Manhattan Project, a secret government-sponsored nuclear science program, and set off in a test in the New Mexico desert on July 16, 1945. The roots of the Manhattan Project went back to 1939, when US scientists urged President Franklin Roosevelt to create a program to study the potential military uses of nuclear fission. The earliest research for the program was done at Columbia University, although work was also carried out at the University of California and the University of Chicago. By 1942 the project was centered in Los Alamos, New Mexico, under the direction of J. Robert Oppenheimer.
The first atomic bomb was developed by the Manhattan Project, a secret government-sponsored nuclear science program, and set off in a test in the New Mexico desert on July 16, 1945. The roots of the Manhattan Project went back to 1939, when US scientists urged President Franklin Roosevelt to create a program to study the potential military uses of nuclear fission. The earliest research for the program was done at Columbia University, although work was also carried out at the University of California and the University of Chicago. By 1942 the project was centered in Los Alamos, New Mexico, under the direction of J. Robert Oppenheimer.
Evidence of the new and enormous power of the United States was near at hand by the time Harry Truman became president following Roosevelt's death on April 12, 1945. Truman employed not only conventional military forces in trying to defeat Japan but also attempted continuing diplomacy—to no avail. Truman therefore decided that use of the atom bomb would end the war quickly and save lives. The first bomb was dropped on Hiroshima, Japan, on August 6, 1945; a second bomb, more powerful than the first, was dropped on Nagasaki three days later. More than 100,000 people were killed outright in the two bombings and tens of thousands more died subsequently as a result of radiation poisoning. After various internal negotiations (along with an attempted coup d'etat), the Japanese leadership agreed to a surrender on August 15. The formal ceremony took place on September 2.