THE NEXT task facing the film makers
was the immense one of casting the story's record-making 212 speaking
roles. A few months earlier, before the return from service of many
of Hollywood's leading actors, it would have been impossible, All
but four of the roles are played by men.
Adding to the difficulty of this job
twas the fact that a majority of the roles were depicting living
personalities, the largest number ever arrayed in one film story.
Even the fictional characters had to be cast with great care. because
of what they represented.
Prominent persons to be portrayed on the
screen ranged from two Presidents
of the United States ~ Harry S. Truman and the late Franklin Delano
Roosevelt - to leaders of every phase of the vast atomic project.
These included Generals Brehon Somervell. W. D. Styer, Groves and
Farrell, Rear Admiral William S. Parsons and Colonel John Lansdale
on the armed forces side: Professor Albert Einstein, Professor Enrico
Fermi, Dr. J. Robert Oppenheimer, brilliant University of California
physicist who headed the Los Alamos development and supervised the
New Mexico bomb test, Dr. Vannevar Bush, director of the Office
of Scientific Research and Development.
Dr. Arthur Compton,
director of the Metallurgy Project at the University of Chicago,
Dr. James B. Conant, President of Harvard University, Dr. Ernest
O. Lawrence, director of the Radiation Laboratory at the University
of California and inventor of the famed cyclotron and many others
from the world of science; K. T. Keller of Chrysler Motors, W. S.
Carpenter, Jr.. of the du Pont Company, James A. Rafferty of Union
Carbide Company and Harry A. Winne of General Electric among the
In every case, the script was shown
to I these men and approved. Frequently' they proffered suggestions
for augmenting scenes and these were incorporated into the screenplay,
Almost without exception,. actors were selected of the same physical
make-up and type as the men they were to depict. although the first
requirement always was proved acting abilitty.