National Museum of Nuclear Science & History
Irvin Mastin worked for the J.A. Jones Construction Company.
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.
E. J. Sekeres served in the 509th Headquarters.
