National Museum of Nuclear Science & History
R. F. Ridgeway worked for the Roane-Anderson Company.
John M. Sprecher was a chemical engineer. During the Manhattan Project, he worked for DuPont in Wilmington, DE.
Raymond Lowrey worked at the Hanford, Washington site for the Manhattan Project from 1943 to 1948. Lowrey began his career in the Oklahoma Ordnance Works before moving to Hanford and settling in Richland, Washington after the war.
Earl Thomas was an American physicist. After receiving his Ph.D. from CalTech in 1943, he moved to New Mexico to work with the Navy on rocket design and production for the Manhattan Project.