National Museum of Nuclear Science & History
O'Brien worked for Stone and Webster Engineering Corporation.
Thomas Farrell (1891 – 1967) was a major general in the US Army. Farrell was hand-picked by General Groves to serve as his deputy, or as the Deputy Commanding General of the Manhattan Project.
Secundino Roybal was a staff worker at Los Alamos during the Manhattan Project.
Ledbetter worked in the 200 East Area at Hanford during the Manhattan Project.
