National Museum of Nuclear Science & History
Duane Sewell began working with the Manhattan Project in 1941. He was one of the first people to arrive at Oak Ridge and experienced first-hand some of the difficulties there with cyclotrons and isotope separation.
Leslie Ritner was a member of the Special Engineer Detachment at Los Alamos. He was among the first engineers sent to Los Alamos from Camp Claiborne, Louisiana in late January 1944, serving for two years before being discharged in the spring of 1946.