Aidan Quinn

as Barnet Rosset

as John Umley

as Professor Tigues

as Sacha

as Bishop Ryan

as Father MacGabbhan

as Theodore Parker (voice)

as Daddy Walsh(6 eps)

as Roger Laver(6 eps)

as Bruce

as Self

as Gabriel Robinson

as Theodore Roosevelt(4 eps)

as John Wilson

as Self (archive footage)

as Moody Burkhart

as Self (archive footage)

as Dermot

as Cameron Brogden

as Derek

as John

as Lieutenant Colonel Owens

as Matt Davidson

as Adem

as Thomas Gregson(154 eps)

as Sandy

as Henry Brown

as Self

as Kevin Sweeney(13 eps)

as Martin B.

as Charlie Wright

as Gus Vanderlip(1 ep)

as William Rainsferd

as Richard Baker

as Ulysses S. Grant

as Steven Abbate

as Professor George Oswald(1 ep)

as Alec

as Narrator

as Prof. Porter

as Nicholas Holden

as Self - Host

as Gerry Moore

as Charlie Hamilton

as Jacob Reiser

as Matt Furey(6 eps)

as Frank Brennan

as Henry Dawes

as Kerry Max Cook

as Daniel Webster(4 eps)

as John Berry

as Henry

as CEO(4 eps)

as David Roby(2 eps)

as Frank Nitzche

as Detective Scofield

as Douglas Thomas

as Commodore Alfred Lind

as Joe F. Brown

as Clint Windsor

as Harry Vardon

as Tom Guthrie

as William Franklin

as Gen. Benedict Arnold

as Nick Barron

as Joe O'Malley

as Jeremy Bell (segment "The Passenger List")(1 ep)

as Tom Bledsoe

as Miles Hendon

as Paul McCartney

as Brian

as John Miller(5 eps)

as Ben Nicholson(1 ep)

as Burton Lowe(2 eps)

as Kieran O'Day

as Paul Cooper

as Gary Hallet

as Henry Morton Stanley

as Annibal Ramirez / Carlos

as Self(3 eps)

as Seth Warner

as Narrator

as Harry Roland

as Richmond

as (segment "John Boorman")

as Professor David Ash

as Don Day

as Maurice Woulfe (voice)

as Alfred Ludlow

as Cap. Robert Walton

as (voice)(2 eps)

as Detective John Hallstrom

as Self - Guest(1 ep)

as Benjamin 'Benny' Pearl

as Bob Finkbine

as Tom Casey

as Martin Quarrier

as James McEwan / Jonathan McEwan

as Jules Kaye

as Nick

as Frankie McGuinness

as Samuel De Valera Paxton

as Crusoe

as Self - Guest(1 ep)

as Richard "Stick" Montgomery

as Chris Keller

as Felipe Mendoza

as Michael Pierson

as Dez

as Johnny Rourke

as Chris Keller(1 ep)

as Self(1 ep)

as Tom Guthrie(1 ep)