Brian Dennehy (generál Leslie Groves), David Strathairn (J. Robert Oppenheimer), Michael Tucker (Leo Szilard), Hume Cronyn (James F. Byrnes), Richard Dysart (prezident Harry S. Truman), Hal Holbrook (generál George Marshall), Barnard Hughes (Henry Stimson), John McMartin (dr. Arthur Compton), David Ogden Stiers (prezident Franklin D. Roosevelt), Olek Krupa (Edward Teller), John Pielmeier (Seth), Tony Shalhoub (Enrico Fermi), Ron White (plukovník Nichols), Lawrence Dane, Ken Pogue, Alan Scarfe, Anne Twomey (Kitty Oppenheimerová), Ron Frazier (plukovník Pash), Gary Reineke (Dwight D. Eisenhower), Ester Spitz (Trude Weissová), Bernie McInerney, John Seitz |