W. T. Lewis

Mildred Bays

Harry Truman

Harry S. Truman (1884-1972) was the 33rd President of the United States of America. Truman first learned of the Manhattan Project after the death of President Roosevelt in April of 1945, when he relinquished his role as Vice President and took the oath of office as the next president of the United States.

R. E. Engel

Engel worked in the United States Engineer District Office.

Mark S. Fred

Mark Fred was a research assistant in the chemistry division of the University of Chicago’s Metallurgical Laboratory (“Met Lab”) during the Manhattan Project.