National Museum of Nuclear Science & History
Sidney Williams was a janitor at the University of Chicago’s Metallurgical Lab (“Met Lab”) during the Manhattan Project.
Nicholson worked for Stone and Webster Engineering Corporation.
Gilbert Plass was a Canadian physicist. Plass was born in 1922 in Toronto. He received a B.S. in physics from Harvard University before being hired to work on the Manhattan Project at the Chicago Met Lab, where he worked as an associate physicist.
J. P. Wheeler worked for the Union Carbide & Carbon Corporation.