National Museum of Nuclear Science & History
Joseph Caldwell was a security guard at the University of Chicago’s Metallurgical Laboratory (“Met Lab”) during the Manhattan Project.
John Lansdale (1912 – 2003) was a colonel in the US Army. Lansdale first learned of the Manhattan project from National Defense Research Committee Chairman James B.
Thomas Braswell worked on the assembly line for Mallinckrodt Chemical, a civilian contractor for the Manhattan Project in St.
