Manhattan Project History

The Manhattan Project was the code name for the secret US program during World War II that developed the first atomic bombs. It was one of the most ambitious and highly secretive research projects ever undertaken.Show more

The origins of the Manhattan Project date back to 1939, when physicists Albert Einstein and Leo Szilard warned President Franklin D. Roosevelt that Nazi Germany was developing an atomic bomb. This prompted Roosevelt to launch a research program into nuclear fission.

In 1942, the Manhattan Project was officially born when the US Army Corps of Engineers initiated a program to develop atomic weapons under the direction of Brigadier General Leslie Groves. The code "Manhattan" was used to hide the project's actual purpose from the public.

The Manhattan Project brought together some of the world's most renowned scientists to work in complete secrecy at laboratories across the US. The main research sites were Los Alamos Laboratory in New Mexico, Oak Ridge Facility in Tennessee, and Hanford Site in Washington.

At Los Alamos, theoretical physicist J. Robert Oppenheimer led a team that designed and built the first atomic bombs. Uranium enrichment occurred at Oak Ridge, while plutonium production occurred at Hanford. The project employed over 130,000 people at its peak.

After six years of intense research and development, the first nuclear weapon test occurred at Alamogordo, New Mexico, on July 16, 1945, under the code "Trinity." The success of this test marked the beginning of the nuclear age.

Less than a month later, the US dropped two atomic bombs on the Japanese cities of Hiroshima and Nagasaki. This led to Japan's unconditional surrender and the end of World War II. The Manhattan Project demonstrated the possibility of nuclear energy and its destructive potential.