Cast
Gary Reineke
Groves's Commanding Officer
Vlasta Vrana
Hans Bethe
Heinar Piller
Fleischmann
Scott Thomson
Chemist
David Ogden Stiers
Franklin D. Roosevelt
Ron Frazier
Colonel Pash
Olek Krupa
Edward Teller
Michael Sinelnikoff
Lord Rutherford
Richard Dysart
President Harry S. Truman
Harry Standjofski
Robert Wilson
Jonathan Wise
Robert Serber
John McMartin
Dr. Arthur Compton
Arthur Holden
Scientist (uncredited)
John Seitz
Ralph A. Bard
Lawrence Dane
Timothy Webber
Colonel Lansdale
David Gow
Jack Wisnovsky
David Strathairn
J. Robert Oppenheimer
Hal Holbrook
Gen. George Marshall
Isabelle Mejias
Mrs. Trowbridge
Tom Butler
Captain DeSilva
Lorne Brass
Klaus Fuchs
Bernie McInerney
Romano Orzari
Leo Szilard's Prime Scientist (uncredited)
Barnard Hughes
Henry Stimson
Michael J. Reynolds
Kenneth Bainbridge
Alan Scarfe
George R. Robertson
Ed Condon
Ken Pogue
Dwight D. Eisenhower
Tony Shalhoub
Enrico Fermi
David Ferry
Army Major
Roland Hewgill
Army General
Michael Tucker
Leo Szilard
Hume Cronyn
James F. Byrnes
Patrick Breen
Richard Feynman
Dee McCafferty
William 'Deke' Parsons
Brian Dennehy
Gen. Leslie Groves
Anne Twomey
Kitty Oppenheimer
Ron White
Colonel Nichols
Lia Sargent
Mrs. Wisnovsky