Day One (1989)

(Gen. Leslie Groves)

(J. Robert Oppenheimer)

(Leo Szilard)

(James F. Byrnes)

(President Harry S. Truman)

(Gen. George Marshall)

(Henry Stimson)

(Dr. Arthur Compton)

(Franklin D. Roosevelt)

(Kitty Oppenheimer)

(Colonel Pash)

(Edward Teller)

(Seth)

(Dwight D. Eisenhower)

(Groves's Commanding Officer)

(Ralph A. Bard)

(Enrico Fermi)

(Trude Weiss)

(Colonel Nichols)

(Eugen Wigner)

(Albert Einstein)

(Richard Feynman)

(Hans Bethe)

(Samuel Goudsmit)

(Klaus Fuchs)

(Lord Rutherford)

(Haakon Chevalier)

(Michael Polanyi)

(Ilse Polanyi)

(Colonel Lansdale)

(Robert Wilson)

(Mrs. Wisnovsky)

(Jack Wisnovsky)

(Shapp)

(Mrs. Trowbridge)

(Robert Serber)

(Ed Condon)

(William 'Deke' Parsons)

(Captain DeSilva)

(T. O. Jones)

(James Tuck)

(Harry Gold)

(Army Major)

(Fleischmann)

(Haagen Kistiakowski)

(George Kistiakowski)

(Kenneth Bainbridge)

(William D. Leahy)

(Paul Tibbets)

(Air Force Guard)

(Chemist)

(Alfred MacCormack)

(Army General)

(John J. McCloy)

(Allan Dulles)

(London Pedestrian)

(British Jr. Officer)

(British Sr. Officer)

(Alexander Sachs)

(General Pa Watson)

(Los Alamo Scientist (uncredited))

(Scientist (uncredited))

(Leo Szilard's Prime Scientist (uncredited))