The Black Scientists Behind Oppenheimer’s Manhattan Project

• There were at least 19 Black scientists and technicians who worked on the Manhattan Project.
• Their contributions helped develop the atomic bombs used to end World War II, but many didn’t know the final purpose of their work.
• Thousands of Black Americans worked low-wage jobs in project facilities and faced Jim Crow segregation.

At the peak of World War II in 1942, the US government launched a program to develop an atomic weapon, responding to intelligence that Germany was developing its own nuclear technology. The program was code-named the Manhattan Project, after the location of its first headquarters in New York City, and was led by prominent scientists like Robert Oppenheimer and Enrico Fermi.

At its height, the Manhattan Project employed nearly 130,000 people, including thousands of Black Americans, most of whom took on menial jobs like janitors, cooks, and laborers. In the labs, there were at least 19 Black scientists and technicians among the 400 or so scientists employed by the project.

The project was unique for bringing together “colored and white, Christian and Jew” for a common cause, Arthur Compton, the Manhattan Project director in Chicago, said.

Although much of their work was shrouded in secrecy — intentionally compartmentalized to keep them in the dark — the scientists on the Manhattan Project made major contributions to the understanding and development of nuclear science.

Jim Crow segregation

In 1941, in order to spur employment opportunities for Black Americans, President Franklin D. Roosevelt issued Executive Order 8802, which stated that “there shall be no discrimination in the employment of workers in defense of industries of Government because of race, creed, color, or national origin.”

The Manhattan Project did create opportunities for Black Americans’ advancements, but many Black workers grappled with Jim Crow segregation.

During the 1940s, thousands of Black men and women migrated to rural communities like Oak Ridge and Hanford, which were the sites of several huge Manhattan Project facilities, and took on jobs as construction workers, laborers, and janitors.

At both these sites, housing was segregated, and most Black Americans lived in cramped “hutments” — small plywood structures with shutter windows, one stove, and no plumbing. Although white couples were allowed to live together, Black couples were not. Many were also refused service at stores and restaurants.

“There are few other areas of the South where the plight of the Negros, as compared with that of their white neighbors, is as wretched as it is here,” Enoc Waters, a columnist for the Chicago Defender, reported.

Black scientists of the Manhattan Project

In the years since, as government documents have become declassified since the Manhattan Project, Black scientists started to be recognized for their contributions and hailed as role models.

Among them was William Jacob Knox, Jr., a chemist with a Ph. D. from the Massachusetts Institute of Technology. His work on uranium separation was crucial to the development of atomic bombs. Knox became the Manhattan Project’s only Black supervisor after he was appointed to lead the all-white Corrosion division of the project at Columbia University.

In 1944, a 21-year-old mathematician named Jesse Ernest Wilkins joined the University of Chicago’s Met Lab to research plutonium. A child prodigy who was the youngest student ever admitted to the University of Chicago at 13 years old, Wilkins earned his Bachelor’s, Master’s, and Ph. D. in just six years. 

Along with the work of other Black scientists like Jasper Jeffries, Carolyn Parker, Samuel Proctor Massie, and Moddie Daniel Taylor, Wilkins’ and Knox’s contributions were crucial to the Manhattan Project.

A complicated legacy

Because of the extreme secrecy surrounding the project, very few people knew the purpose of their work. “Probably no more than a few dozen men in the entire country knew the full meaning of the Manhattan Project,” Life magazine estimated in 1945.

But when its purpose was made clear, 70 scientists and researchers — including Wilkins and Jeffries — signed the Szilard Petition in 1945, urging President Truman against the use of the atomic bomb against Japan. The petition, however, was never seen by the president before the US dropped the first atomic bomb on Hiroshima.

After the bombings, Americans were divided in their response to the Manhattan Project. Some applauded the inclusion of African Americans in the Manhattan Project as evidence of scientific rationalism overcoming racism, while others saw it as a necessary means to end the war. At the same time, prominent figures like W.E.B. Du Bois and Langston Hughes criticized the bombing of Japan, questioning whether the Allies were fighting a “racial war” when they used the bomb against the Japanese, but not Europeans.

Many Black scientists involved in the Manhattan Project went on to build careers that advanced technology and expanded opportunities for other Black scientists. After the war, Knox, the chemist from MIT, earned 21 patents throughout his career, and Wilkins advocated for peaceful use of nuclear power and helped establish a program for young Black scientists.