Manhattan Project scientists hired Columbia University's football team to lug uranium into the physics lab on campus in the 1940s

• The development of nuclear weapons during World War II was codenamed the Manhattan Project.
• Nuclear fission experiments were conducted at Columbia University in the late 1930s and early 1940s.

Christopher Nolan's highly-anticipated film "Oppenheimer" chronicles the development of the atomic bomb in the United States during World War II. But most viewers may not know a surprising detail about the top-secret initiative, codenamed the Manhattan Project.

In 1939, researchers conducted the first nuclear fission experiment in the US with a cyclotron, also known as an "atom smasher," in the basement of Pupin Hall, the physics building at Columbia University. The following year, the President's Advisory Committee on Uranium awarded $6,000 to fund atomic physicist Enrico Fermi's continued research at Columbia.

Then, in response to Germany's successful efforts to split the atom, giving them the capacity to create atomic weapons, President Franklin D. Roosevelt officially established the Manhattan Project, headed by J. Robert Oppenheimer.

Fermi, who studied radioactive substances as part of the top-secret experiments, needed help moving large amounts of uranium into the laboratory at Columbia. According to a 1993 article about the Manhattan Project in the student publication The Columbia Spectator, the university's administration asked members of the football team, the Columbia Lions, to assist him.

From the spring of 1941 through the summer of 1942, the football players were hired to lug heavy canisters of uranium into Pupin Hall. Due to the secrecy of the project, they were not told what it was that they were carrying.

"It really was a pleasure to direct the work of these husky boys, canning uranium, just shoving it in — handling packs of 50 or 100 pounds with the same ease as another person would have handled three or four pounds," Fermi is quoted as saying in The Columbia Spectator.

Today, of course, more is known about the danger of handling radioactive chemicals. Whether the football players experienced any health issues due to their exposure to uranium is unknown. But according to The New York Times, the Manhattan Project employed 700 people at Columbia — including the unsuspecting Columbia Lions.

"Oppenheimer" premieres in theaters July 21.