National Museum of Nuclear Science & History
MacDonald was a member of the Instrument Section at the University of Chicago’s Metallurgical Laboratory.
John Ursch served in the 1395th Military Police Aviation.
Alfred Pfanstiehl was a junior physicist at the Chicago Met Lab during the Manhattan Project. Pfanstiehl was a signatory of the Szilard Petition, an attempt to avert military use of the atomic bomb against Japan.