National Museum of Nuclear Science & History
John P. McBride was a research assistant in the Chemistry Division at the Chicago Met Lab. He was later assigned to Oak Ridge, where he worked on plutonium purification and on isolating uranium-233 isotopes from thorium.
Harmon worked for Stone and Webster Engineering Corporation.
Calvin B. Popwell served as a corporal in the 393rd Bombardment Squadron. He was a member of the ground crew regularly assigned to the B-29 Big Stink, and he and his crew were later reassigned to Luke the Spook.
Spencer worked for Stone and Webster Engineering Corporation.