The Manhattan Project

What is the Manhattan Project?

The Manhattan Project was a U.S.-led project to manufacture and drop atomic bombs during World War II.

It was a major project launched in 1942 by the U.S., the U.K., and Canada, which mobilized many of their scientists and engineers. The Manhattan Project continued until 1946.

The project was a success, and an atomic bomb was produced and tested for the first time on July 16, 1945. That same year, bombs were dropped on Hiroshima on August 6 and Nagasaki on August 9, killing hundreds of thousands of people in total and triggering the creation of the Cold War structure after the war. The scientific division was headed by Robert Oppenheimer.

Predecessor organization of the Manhattan Project

The Manhattan Project was initiated in October 1942 but its beginnings date back to 1938, when German scientists Otto Hahn and Fritz Sjutrasman accidentally discovered atomic fission.　Fearing that Nazi Germany would possess nuclear weapons first, exiled Jewish physicist Leo Szilard and others sent a letter to President Roosevelt in 1939. They had the exiled Jewish physicist, Einstein, put his signature on the letter. This was the first letter to encourage the U.S. government to move toward nuclear development.

After reading the letter, President Roosevelt assembled a group of military and scientific experts to form the Uranium Commission to study the possibility of a nuclear fission reaction.

Roosevelt ordered Lehman Briggs, Director of the National Bureau of Standards, to establish the S-1 Uranium Committee to study the problems that Szilard proposed.

The Manhattan Project begins

In October 1942, Roosevelt approved the nuclear weapons development project during a meeting with National Defense Research Committee (NDRC) Chairman Vannevar Bush (related to George W. Bush) and Vice President Henry A. Wallace.

Why was it called the “Manhattan Project”?

The name “Manhattan Project” came from the fact that the project’s headquarters was originally located at 270 Broadway in Manhattan.

Leslie R. Groves, who was appointed chief executive officer of the project, suggested the name and it was adopted.

The first major funding for the Manhattan Project came in December 1942, when President Roosevelt made an initial allocation of $500 million.

Soon thereafter, the headquarters of the plan was moved to the nation’s capital, Washington, D.C., but development sites were scattered throughout the United States.

Robert Oppenheimer

Robert Oppenheimer (April 22, 1904 – February 18, 1967) was an American theoretical physicist. He is known as the “father of the atomic bomb” because of his leadership in the Manhattan Project as the first director of Los Alamos National Laboratory during World War II and his outstanding leadership in the development of the atomic bomb.

In the late 1930s, he was conducting extremely pioneering research in the field of astrophysics on neutron stars or black holes as they are called today, but when World War II broke out, the Manhattan Project was launched in 1942 with the aim of developing an atomic bomb. Oppenheimer was appointed the first director of Los Alamos National Laboratory in 1943 and led the research team that produced the atomic bomb. Their group developed the world’s first atomic bombs, which were to be dropped on the cities of Hiroshima and Nagasaki in the Empire of Japan after a nuclear test in New Mexico, known as the “Trinity Test”.