Day One

Brian Dennehy

Gen. Leslie Groves

David Strathairn

J. Robert Oppenheimer

Michael Tucker

Leo Szilard

Hume Cronyn

James F. Byrnes

Richard Dysart

President Harry S. Truman

Hal Holbrook

Gen. George Marshall

Barnard Hughes

Henry Stimson

John McMartin

Dr. Arthur Compton

David Ogden Stiers

Franklin D. Roosevelt

Anne Twomey

Kitty Oppenheimer

Lawrence Dane

Ron Frazier

Colonel Pash

Olek Krupa

Edward Teller

Bernie McInerney

John Pielmeier

Seth

Ken Pogue

Dwight D. Eisenhower

Gary Reineke

Groves's Commanding Officer

Alan Scarfe

John Seitz

Ralph A. Bard

Tony Shalhoub

Enrico Fermi