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.
C. L. McCallum worked for the Tennessee Eastman Corporation at the Y-12 Plant.
H. A. Pritchard worked for the J.A. Jones Construction Company.
Clarence Grover Sproul worked as a machinist on the Manhattan Project in Los Alamos, NM from January through June 1945.