Manhattan Project

  Origins and Context

In August 1942, the US Army Corps of Engineers established the Manhattan Engineer District to develop atomic weapons in response to fears of a German nuclear program.¹ The project emerged from earlier research efforts and the Einstein-Szilard letter warning President Roosevelt about atomic weapons potential.²

  Program Structure

Major General Leslie Groves directed the project, with physicist J. Robert Oppenheimer leading the Los Alamos Laboratory where the weapons were designed.³ The program operated through three main sites: Oak Ridge for uranium enrichment, Hanford for plutonium production, and Los Alamos for weapon design and assembly.⁴

  Operations and Impact

The project employed over 130,000 people and cost nearly $2 billion ($27 billion in 2023). Scientists pursued both uranium enrichment and plutonium production pathways.⁵ The program culminated in the Trinity Test in July 1945 and the atomic bombings of Hiroshima and Nagasaki in August 1945.⁶

  Legacy

The Manhattan Project transformed warfare and international relations, ushering in the atomic age and Cold War. It established the model for large-scale scientific research and development programs, leading to the creation of the national laboratory system.⁷

  References

1. "The Manhattan Project: An Interactive History", US Department of Energy Office of History and Heritage Resources, 2015 ↩

2. Einstein, A. & Szilard, L., "Letter to President Roosevelt", August 2, 1939 ↩

3. Groves, Leslie R., "Now It Can Be Told: The Story of the Manhattan Project", 1962 ↩

4. Rhodes, Richard, "The Making of the Atomic Bomb", Simon & Schuster, 1986 ↩

5. Manhattan District History, Book I General Volume 4, "Research", 1944 ↩

6. "Trinity Test Report", Los Alamos Scientific Laboratory, LA-1, 1945 ↩

7. US Department of Energy, "The Origins of the National Laboratory System", DOE/MA-0001 ↩