Original Items: One-of-a-kind set. This is an extremely rare matched numbered set of World War Two Manhattan District (aka Manhattan Project) later moved to Oak Ridge Tennessee US Engineer Corps Guard Badges. Both badges are numbered 402. The set consists of a hat badge and a chest badge. The hat badge measures 1 7/8" x 2 3/8" and has a single screw post with disc backing attachment. The chest badge measures 2 1/4" x 2 1/2" and has a vertical pin with tang-style 'c' catch. They are both constructed of nickel-plated sheet steel with stamped lettering and are offered in very good to excellent condition.

Special Engineer Detachment – New York
Lawrence S. O’Rourke began working on the Manhattan Project at Columbia University in Manhattan, NY after he was called up from the Army Reserves in 1944. O’Rourke was among the first group of Special Engineer Detachment soldiers who worked at Columbia, where he helped research and develop the gaseous diffusion process for the separation of uranium. After nine months, O’Rourke’s group moved from the Pupin Physics Lab to the Nash Garage Building, where they helped develop the barrier material that would be used at the K-25 plant in Oak Ridge. In 1945, O’Rourke was transferred to Oak Ridge, TN and continued to work on research and development of a barrier material at K-25. O’Rourke also spent time at the Houdaille-Hershey Plant in Decatur, IL where he helped install and train people on how to test the barrier material that was being developed. In this interview, O’Rourke discusses his reaction to the dropping of the atomic bombs on Japan and working at the K-25 Plant in Oak Ridge, TN.

The Manhattan Project was a research and development undertaking during World War II that produced the first nuclear weapons. It was led by the United States with the support of the United Kingdom and Canada. From 1942 to 1946, the project was under the direction of Major General Leslie Groves of the U.S. Army Corps of Engineers. Nuclear physicist Robert Oppenheimer was the director of the Los Alamos Laboratory that designed the actual bombs. The Army component of the project was designated the Manhattan District; Manhattan gradually superseded the official codename, Development of Substitute Materials, for the entire project. Along the way, the project absorbed its earlier British counterpart, Tube Alloys. The Manhattan Project began modestly in 1939, but grew to employ more than 130,000 people and cost nearly US$2 billion (about $23 billion in 2018 dollars). Over 90% of the cost was for building factories and to produce fissile material, with less than 10% for development and production of the weapons. Research and production took place at more than 30 sites across the United States, the United Kingdom, and Canada.