Gen. Leslie R. Groves

Paul Newman

Acting

J. Robert Oppenheimer

Dwight Schultz

Acting

Kitty Oppenheimer

Bonnie Bedelia

Acting

Michael Merriman

John Cusack

Acting

Kathleen Robinson

Laura Dern

Acting

Peter de Silva

Ron Frazier

Acting

Richard Schoenfield

John C. McGinley

Acting

Jean Tatlock

Natasha Richardson

Acting

Jamie Latrobe

Ron Vawter

Acting

William "Deke" Parsons

Michael Brockman

Acting

Dr. Kenneth Whiteside

Del Close

Acting

Robert Tuckson

John Considine

Acting

Franz Goethe

Allan Corduner

Acting

Seth Neddermeyer

Joe D'Angerio

Acting

Johnny Mount

Jon DeVries

Acting

Robert Harper

James Eckhouse

Acting

Robert Wilson

Todd Field

Acting

Dora Welsh

Mary Pat Gleason

Acting

Douglas Panton

Clark Gregg

Acting

George Kistiakowsky

Péter Halász

Acting

Leo Szilard

Gerald Hiken

Acting

Oakridge Doctor

Arthur Holden

Acting

Whitney Ashbridge

Ed Lauter

Acting

James Tuck

Donald MacKechnie

Acting

Boris Pash

Madison Mason

Acting

Otto Frisch

Krzysztof Pieczyński

Acting

Bronston

Don Pugsley

Acting

Brehon Somervell

Logan Ramsey

Acting

Melrose Hayden Barry

Fred Thompson

Acting

Donald Hornig

Jim True-Frost

Acting

Edward Teller

Barry Yourgrau

Acting

Scientist

Marek Alboszta

Acting

Dr. Avenell

Steven Baigelman

Writing

Messenger

Frank Benettieri Jr.

Acting

Frank Oppenheimer

Roger Cubicciotti

Acting

Enrico Fermi

Franco Cutietta

Acting

Dr. Louis Hempelman

Robert Peter Gale

Writing

Peter Oppenheimer

Wesley Harrison

Acting

Peter Oppenheimer

Brent Harrison

Acting

Scientist

Tom McFarlane

Acting

Raincoat Man

David C. Parnes

Acting

Harold McDonald

Allen Poirson

Acting

Robert Serber

David Politzer

Acting

Times Reporter

Bill Rubenstein

Writing

Observation Officer

Ken Strausbaugh

Acting

Henry Stimson

Walter Sullivan

Acting

Dennis Talmudge

Brian Wandell

Acting

Mack Stoddard

John Williams

Acting

(voice)

Walker Edmiston

Acting

(voice)

Matthew Faison

Acting

(voice)

Stan Jones

Acting

(voice)

Alan Oppenheimer

Acting