David Strathairn

as Milton Lynxley (voice)

as Bill

as Ralph Waldo Emerson (voice)

as Bill

as Warren

as Jan Karski

as Tom Milton

as Dave

as Pete

as Messenger 1

as Joe Haley

as Ellis

as Fred Stern

as Admiral William Stenz

as Self

as Franklin Ahls

as God

as Marty Rothstein

as President Roosevelt (voice)

as Theo

as Nathan Zuckerman

as Richard Englebright

as Ty Burley

as Nathan

as Richard Weissman

as William Flynn

as Henry

as Admiral William Stenz

as Self

as Self - Narrator (voice)

as Noah Vosen

as John Dos Passos

as Delmar

as William Seward

as Professor Carlock

as King Alonso

as Narrator

as Peter Ward

as Roman Lodari

as Ralph McIntosh

as Self

as Dr. Flintstein

as Steven

as J. Robert Oppenheimer

as Self

as Self

as Arthur Spiderwick

as Joe Lobruto

as Danny Dunkelman

as Narrator

as Self

as Noah Vosen

as Mr. Jennings

as Arnie

as Henry / Harry

as Paul Mullin

as President Dedmon

as Judge James Horton

as Narrator

as Finn

as Narrator

as Edward R. Murrow

as Estes Kefauver

as Henry R. Hocknell Jr.

as Pierce Patchett in L.A. Confidential (archive footage)

as Dr. Melvin Frank

as Reverend Bobby Paradise

as Auster

as Self

as Jack Hoschouer

as Bruce Hickman

as Mannie

as Dr. Charlie

as Mark Zingerline

as Harrison Lloyd

as Peter Crowley

as Truman Lester

as Captain Keller

as Theseus

as Howard Goodwin

as Joe Gastineau

as Earl Himes

as Charles Kaminski

as Rev. Russell

as Armand Minetti

as Jackson Kinley

as Wes Westlund

as Pierce Patchett

as Marcel

as Martin

as Russel Gates

as Bernard B. O'Hare

as Russell Terziak

as Joe St. George

as Charles Lewin

as John McCowan

as Tom Hartman

as Young Arthur Huntington

as Getso

as Johnny

as Ray McDeere

as Whistler

as Rennie

as Keith

as Mack Laflin

as Carl Linstrum

as Ira Lowenstein

as Dr. Arthur Kobrine

as Asteroid

as Craig Harriman

as Bill Thomas

as Father Frank Aubert

as J. Robert Oppenheimer

as The Stranger

as Eddie Cicotte

as Charlie

as Sam

as Martin Chernak

as Stuart Chase

as Police Chief Sid Hatfield

as Tony Pine

as Weejun

as Man In Black

as Dr. Singe

as Wesley

as Marvin Zuckerman

as Jerry

as Ron