National Museum of Nuclear Science & History
Before the war Oswald Greager was a high-ranking DuPont chemist. He took leave from DuPont in 1942 to join the Army's Chemical Warfare Service.
Frederick Rich worked for the Union Carbide & Carbon Corporation.
Horace Hood set up equipment for the J.A. Jones Construction Company in Oak Ridge, Tennessee. He and his family lived in Kingsport, Tennessee while Hood commuted to Oak Ridge through a series of security checkpoints each day.