National Museum of Nuclear Science & History
Ed Helfenberger worked for the Roane-Anderson Company.
Barr worked for Stone and Webster Engineering Corporation.
Colonel Arthur “Pete” V. Peterson was the Army’s area engineer at the University of Chicago’s Metallurgical Laboratory (“Met Lab”) during the Manhattan Project.
Severn A. Jackson served in the 1st Ordnance Squadron.
H. M. Schleiden worked for the A. S. Schulman Electric Company.