In January and February of 1943, there was a small-scale operation known as Project Alberta that was launched by the National Defence Research Committee (NDRC) under Enrico Fermi. The goal of this project was to investigate the feasibility of using uranium and heavy water to create an atomic bomb. Fermi and his colleagues, including Leó Szilárd and Samuel Allison, conducted experiments at Columbia University and other facilities, but by July, they had determined that the production of heavy water would be too slow and costly for a large-scale project.

In August 1943, the Manhattan Project was established under the direction of Major General Leslie Groves, with the goal of developing the atomic bomb. The project's scientists, including Oppenheimer, Fermi, Szilárd, and many others, faced several challenges, including the sourcing of sufficient quantities of uranium. Uranium is a relatively rare element, and the known reserves at the time were limited.

To obtain enough uranium for the bomb, the Manhattan Project team embarked on a large-scale effort to procure and refine uranium ore. The United States government negotiated agreements with Canada, Belgium, and the United Kingdom to secure access to their uranium resources. Additionally, a massive mining operation was launched in the Belgian Congo (present-day Democratic Republic of the Congo) to extract uranium ore.

The extracted uranium ore was shipped to the United States and processed at several facilities, including the Oak Ridge National Laboratory in Tennessee. There, the ore underwent various stages of purification and enrichment to produce uranium suitable for use in the atomic bombs.

Despite these efforts, the scientists encountered difficulties in producing enough uranium at the desired purity levels. The process was complex, time-consuming, and required specialized equipment, which led to delays and setbacks in the project. Nevertheless, by 1945, the Manhattan Project had successfully produced sufficient uranium for the creation of the atomic bombs, "Little Boy" and "Fat Man," which were used in the bombings of Hiroshima and Nagasaki, respectively.