Copy of (1939) letter of Albert Einstein to Franklin D. Roosevelt, regarding work of Enrico Fermi and L. Szilard (toward setting up nuclear chain reaction); brochure regarding French exhibit at Atom Fair; letter of AEC chairman Glenn T. Seaborg regarding Annual Report to Congress; letters and articles regarding 20th anniversary celebrations of first chain pile (CP-l) speech by AEC commissioner Robert E. Wilson on "Policy Objectives and Government Organization," at Atomic Industrial Forum; International Atomic Energy Agency Bulletin Special Number; press kit issued by AEC and White House, including "Remarks of the President to a Group of Scientists Who Witnessed the Original Fermi Experiment ... "; reprint of AEC report of March 1955, "The First Pile" and "Background Material."