David Strathairn

as Michael

as Special Agent Roy K. Moore

as Warren

as Porter Gates

as Sanford 'Sandy' Harrison(1 ep)

as Self (voice)

as Milton Lynxley (voice)

as Ralph Waldo Emerson (voice)

as Bill

as Bill

as Dr. Benjamin Cole(4 eps)

as Jan Karski

as Tom Milton

as Pete

as Dave

as Messenger 1

as Joe Haley

as Henry Fisher(10 eps)

as Self

as Fred Stern

as Admiral William Stenz

as Ellis

as Marty Rothstein

as Franklin Ahls

as God

as Semiyon Kleiman(7 eps)

as President Roosevelt (voice)

as Theo

as Nathan Zuckerman

as Richard Englebright

as Black Jack Foley(8 eps)

as Commander Klaes Ashford(6 eps)

as Klaes Ashford(7 eps)

as Anthony Sayre(10 eps)

as Richard Weissman

as Nathan

as Ty Burley

as Admiral William Stenz

as William Flynn

as Self - Narrator (voice)

as Peter Kotsiopulos(12 eps)

as Self

as William Seward

as John Dos Passos

as Noah Vosen

as Delmar

as Lee Rosen(24 eps)

as Peter Ward

as King Alonso

as Ralph McIntosh

as Narrator

as Himself - Narrator

as Professor Carlock

as Roman Lodari

as Self

as Dr. Flintstein

as Steven

as Self

as Self

as J. Robert Oppenheimer

as Arthur Spiderwick

as Arnie

as Self

as Mr. Jennings

as Noah Vosen

as Henry / Harry

as Danny Dunkelman

as Joe Lobruto

as Narrator

as President Dedmon

as Finn

as Judge James Horton

as Narrator

as Paul Mullin

as Estes Kefauver

as Edward R. Murrow

as Narrator

as Henry R. Hocknell Jr.

as Nash(1 ep)

as Dr. Melvin Frank

as Reverend Bobby Paradise

as Self

as Auster

as Jack Hoschouer

as Jack Hoschouer(2 eps)

as Mannie

as Patrick Kloster(1 ep)

as Bruce Hickman

as Dr. Charlie

as Will Preecher(8 eps)

as Mark Zingerline

as Truman Lester

as Captain Keller

as Harrison Lloyd

as Peter Crowley

as Howard Goodwin

as Joe Gastineau

as Theseus

as Charles Kaminski

as Robert Wegler(3 eps)

as Wes Westlund

as Reverend Russell

as Armand Minetti

as Jackson Kinley

as Earl Himes

as Pierce Patchett

as Marcel

as Martin

as Bernard B. O'Hare

as Russel Gates

as Russell Terziak

as Joe St. George

as Charles Lewin

as Tom Hartman

as John McCowan

as Getso

as Ray McDeere

as Johnny

as Young Arthur Huntington

as Rennie

as Whistler

as Mack Laflin

as Ira Lowenstein

as Keith

as Carl Linstrum

as Asteroid

as Dr. Arthur Kobrine

as Father Frank Aubert

as Craig Harriman

as Bill Thomas

as The Stranger

as J. Robert Oppenheimer

as Eddie Cicotte

as Sam

as Charlie

as Martin Chernak

as Police Chief Sid Hatfield

as Moss Goodman(20 eps)

as Stuart Chase

as Tony Pine

as Phillip Borchek(1 ep)

as Weejun

as Marty Lang(1 ep)

as Man In Black

as Dr. Singe

as Wesley

as Marvin Zuckerman

as Jerry

as Carl Linstrum(1 ep)

as The Stranger(1 ep)

as Ron

as Self(1 ep)

as Carl Linstrum(1 ep)

as Self(1 ep)