Oak Ridge, Tennessee

Alpha calutron operators at their control panels, Y-12, Oak Ridge. 1943-1944.

Ed Westcott, Department of Energy

American World War II Heritage City

Oak Ridge was built under a cloak of secrecy by the United States government during World War II. It was one of three primary sites built for the Manhattan Project, the massive wartime effort that produced the world’s first atomic weapons. In 1942, the U.S. Army Corps of Engineers bought an estimated 60,000 acres of rural farmland to construct a temporary city and three facilities to develop atomic technology. Uranium enriched at Oak Ridge would ultimately be used in the “Little Boy” atomic bomb.

Construction of major facilities at Oak Ridge began in 1943. Oak Ridge served as the headquarters of the Manhattan Project. By 1945 more than 75,000 people living in the “Secret City”, making it Tennessee’s 5th largest city during the war. Over 80,000 employees worked tirelessly at Oak Ridge to undertake the massive challenges presented by the Manhattan Project, although very few of them knew what they were working on for the government.

Oak Ridge was the site where U.S. military leaders and scientists oversaw the enrichment of uranium and established that plutonium could be produced in a uranium reactor for the development of the world’s first atomic weapons. Roughly 60% of the funding for the Manhattan Project was used for Oak Ridge.

To house all the new workers and their families, multiple small, self-sufficient neighborhoods were built. Each one had its own housing and shopping center and was somewhat isolated from the other neighborhoods. The wartime construction and operation of Oak Ridge was a testament to the dedication, sacrifice and discipline of the people living and working there. Workers, some of whom were segregated by race, adapted to living in muddy and primitive conditions, particularly in the early stages of the Project.

After the war, Oak Ridge transitioned from a “temporary” military town into a self-governing city. Within 10 years of its incorporation in 1959, Oak Ridge was already taking steps to preserve its history. The X-10 Graphite Reactor was designated a National Historic Landmark in 1966. The city was itself listed on the National Register of Historic Places in 1991. The city once again reaffirmed its commitment to historic preservation in 2006, when it was named a Preserve America community. Other prominent locations in the city of Oak Ridge include the K-25 History Center, three historic gate houses, the Wheat Church, and the Chapel on the Hill. Several local museums - the American Museum of Science and Energy (AMSE), the Children’s Museum of Oak Ridge, the Oak Ridge History Museum, and the K-25 History Center - provide educational and interpretive programs and exhibits.

In 2015, the U.S. Congress established the Manhattan Project National Historic Park (MAPR) as a three-site, one park concept in partnership with the National Park Service and the U.S. Department of Energy. Consisting of sites in Oak Ridge, Los Alamos, NM, and Hanford, WA, Manhattan Project National Historic Park seeks to educate its visitors about the history of atomic development and the science behind nuclear technology. The Oak Ridge site includes the X-10 Graphite Reactor, the footprint of the original K-25 building, two original calutron buildings at the Y-12 site, and the former Alexander Guest House.