George R. Holdren

George W. Campbell

George W. Campbell was a research assistant at the University of Chicago’s Metallurgical Laboratory (“Met Lab”) during the Manhattan Project.

H. P. Graves

H. P. Graves worked in the United States Engineer District Office.

V.W. Shell

Joseph Caldwell

Joseph Caldwell was a security guard at the University of Chicago’s Metallurgical Laboratory (“Met Lab”) during the Manhattan Project.