American Physical Society recognizes 'Chicago Pile' at University of Chicago as historic site

Event at UChicago commemorates site of first controlled nuclear chain reaction during Manhattan Project

The American Physical Society has designated Chicago Pile-1 and Stagg Field at the University of Chicago, as well as “Site A” in the nearby Palos Forest Preserve, as historic sites to recognize the world’s first self-sustaining, controlled nuclear chain reaction. 

“Few events have changed both science and society as greatly as the controlled nuclear fission research successfully performed by Fermi and his team at the University of Chicago,” said Lee Sawyer, chair of the American Physical Society Historic Sites Committee. 

Each site will receive a plaque acknowledging its exemplary contributions to physics. The plaques were bestowed in an event held at the University of Chicago on July 14.

“The development of the world’s first controlled, sustained nuclear reaction at the University of Chicago defined a field of research and had a profound impact on world history, in ways that we continue to see today,” said Juan de Pablo, executive vice president for science, innovation, national laboratories, and global initiatives at the University of Chicago. “We are honored by the American Physical Society’s recognition of the pivotal work that took place under the stands of the old Stagg Field and at the suburban ‘Site A,’ the forerunner of today’s thriving Argonne National Laboratory.” 

Making history

In 1942, the Chicago Pile-1 nuclear reactor, which was built at the University of Chicago’s original Stagg Field, succeeded in triggering the first human-made, self-sustaining nuclear chain reaction as part of the Manhattan Project.

The reactor project was then dismantled and moved southwest in 1943 to “Site A” in what is now the Cook County Forest Preserves. After the war, the operation became the first national laboratory – named Argonne National Laboratory – and was given the mission of developing nuclear technology for peaceful purposes. The laboratory then relocated several miles northwest of Site A. (The Site A location was released to the Cook County Forest Preserve District in 1956.) In the following decades, researchers at Argonne continued to work with reactors, leading to advances in nuclear energy, neutron scattering research and nuclear physics applications for medicine and other uses.

Meanwhile, at the University of Chicago, the squash court and old football stands that had housed Chicago Pile-1 were demolished and replaced by the University of Chicago’s Joseph E. Regenstein Library and the Joe and Rika Mansueto Library.

A bronze sculpture by noted artist Henry Moore called “Nuclear Energy” commemorates the spot and is open to visitors. The sculpture is located on the east side of Ellis Avenue between 56th and 57th streets, just south of the Max Palevsky residence hall and north of the glass dome of Mansueto Library.