Oak Ridge: The Secret Manhattan Project City Left Off the Map, Tennessee

In September 1942, General Leslie Groves, newly in charge of the Manhattan Project, approved the purchase of about 59,000 acres of farmland and woods along the Clinch River in East Tennessee. The families who lived there were forced to sell and move. The Army needed the land for something it couldn't explain: enormous plants to produce material for an atomic bomb. Engineers had to build those plants and a town to house the workers, both at once, and in secret. Plans called at first for about 13,000 people in prefabricated houses, trailers and dormitories. The estimate kept climbing. From about 3,000 people in late 1942, the population surged to 75,000 by 1945. In less than three years, Oak Ridge had become the fifth-largest city in Tennessee. Yet officially, it barely existed. Oak Ridge didn't appear on maps. The entire reservation was fenced, with guarded gates. Residents and workers wore badges and had them checked at gates and buildings, and visitors needed special approval. Most of the people living there had no idea what they were working on. They knew only that it was important and that they weren't supposed to talk about it. Inside the fence, Oak Ridge was a real town, with neighborhoods, schools, shops, churches and community centers. Around it, the plants code-named Y-12, K-25 and X-10 worked to produce enriched uranium and test a plutonium reactor. On August 6, 1945, residents learned the truth from the newspapers. The atomic bomb dropped on Hiroshima had been fueled with uranium made at Oak Ridge. After the war, the Atomic Energy Commission took over the town from the military. In 1949, the gates opened to the public, and the American Museum of Atomic Energy, now the American Museum of Science and Energy, opened the same year. Oak Ridge was incorporated as a city in 1959. Today, Oak Ridge has about 31,000 residents and is still home to Oak Ridge National Laboratory and the Y-12 National Security Complex. It's part of the Manhattan Project National Historical Park, and its old gatehouses still stand.