Manhattan Project National Historical Park Tour

With the hope of developing technology that would end World War II, the U.S. government built Oak Ridge under a cloak of great secrecy. When the Japanese attacked Pearl Harbor on Dec. 7, 1941, the city of Oak Ridge didn’t even exist. But in 1942, the U.S. Army Corps of Engineers purchased 59,000 acres of century-old family farms and small rural communities for a top-secret mission to produce the world’s first atomic weapons, known as the Manhattan Project.

Established amid concerns that Nazi scientists would create a bomb capable of horrific destruction, the Manhattan Project sought to develop an atomic bomb before the Germans could. In valleys located away from Oak Ridge, the government built three production facilities for the Manhattan Project: Y-12, X-10, and K-25. At the time, the K-25 uranium-separating facility was the largest building in the world, covering about 44 acres. Inside these top-secret plants, scientists and workers used two methods, and then eventually three, to produce fissionable material needed to develop atomic weapons.

To accommodate the massive influx of workers for the Manhattan Project, the government had to build a Secret City from scratch. U.S. engineers designed 3,000 prefabricated homes that were shipped from an Indiana factory complete with walls, floors, room partitions, interior wiring, plumbing, and furniture. Just two and a half years after Oak Ridge was founded, the city skyrocketed to a population of 75,000, making it the fifth-largest city in Tennessee.