Manhattan Project: cumulative costs by facility 1945

From August 1942 until 1945, almost 1.9 billion U.S. dollars was spent on the development of the world's first nuclear weapons through the Manhattan Project. This included almost 1.4 billion in plant-related costs, and an additional 508 million U.S. dollars in operational costs.

Oak Ridge

The complex at Oak Ridge, Tennessee, received around 1.2 billion U.S. dollars (63 percent) of the total expenditure of the Manhattan Project. These plants are where the uranium used in the atomic bombing of Hiroshima was enriched to "weapons grade". The town of Oak Ridge itself had a population of approximately 3,000 in 1941, but this increased to as many as 75,000 people at the height of the project. The exact purpose of these facilities had remained a secret to most of its residents and employees, who did not learn of what their work had contributed to until after the bombings of Hiroshima and Nagasaki. The plutonium used in the Nagasaki bombing was developed in Hanford, which received over 20 percent of the project's budget.

Los Alamos

While around 85 percent of the Manhattan Project's resources were allocated to the uranium and plutonium production facilities in Oak Ridge and Hanford, the most famous developments of the project took place the Los Alamos facility in New Mexico, through "Project Y". Under the direction of Robert Oppenheimer, the Los Alamos Project successfully developed and tested the world's first nuclear weapon (nicknamed "The Gadget") in June 1945, before constructing the two bombs that would be used in the atomic attacks against Japan around six weeks later. Despite these developments, Los Alamos received just four percent of the Manhattan Project's total budget.