Which sites played major roles in the Manhattan Project?

The Manhattan Project, the U.S. effort to develop the first atomic bomb, relied on three primary, specialized sites selected by General Leslie R. Groves to manage the research, production, and assembly of fissionable materials.12

Key Manhattan Project Sites

• Oak Ridge, Tennessee: Originally known as the Clinton Engineer Works, this site was established to enrich uranium. It housed large-scale factories designed to produce the uranium-235 used in the bomb dropped on Hiroshima.123
• Hanford Engineer Works, Washington: Located in a remote area of south-central Washington, this facility was dedicated to the large-scale production of plutonium. It utilized water from the Columbia River for cooling its reactors. The plutonium produced here fueled the Trinity test and the bomb dropped on Nagasaki.143
• Los Alamos, New Mexico: Known as Project Y, this isolated laboratory served as the central hub for scientific research. Under the direction of J. Robert Oppenheimer, scientists and engineers here developed the methods to fabricate fissionable materials into deliverable weapons.124

Additionally, early experimental work was conducted at the University of Chicago, where the first self-sustaining nuclear chain reaction was achieved in 1942.1