American Playhouse

Robert Oppenheimer

Narrator (voice)

Kitty Oppenheimer / Kitty Harrison

Enrico Fermi

Edward Teller

Colonel Kenneth Nichols

Robert Serber

General Leslie Groves

Hans Bethe

Robert Wilson

Frank Oppenheimer

Ernest Lawrence

Isidor Rabi

Jean Tatlock

Haakon Chevalier

Jacky Oppenheimer

Charlotte Serber

John Manley

Robert Bacher

Grandpa / Les

Bit (uncredited)

Alex / Markos

General Santa Anna / Gregorio Cortez

Manuel Flores / Romaldo Cortez