National Museum of Nuclear Science & History
Parr worked in the 200 East and 100 D Areas at Hanford during the Manhattan Project.
Wallen worked at the 300 Area at Hanford during the Manhattan Project.
As Secretary of War under Presidents Franklin D. Roosevelt and Harry Truman, Henry L. Stimson (1867-1950) oversaw the entire Manhattan Project, and was responsible for appointing key project leaders and authorizing project construction sites across the US.