The British actor plays Louis Zamperini, an Olympic runner who was tortured in a Japanese prison camp during second World War.
Jolie, 39, said she could not stop smiling, when she was casting Jack for the movie, reported the Daily Mirror.
"Louis is this extraordinarily witty, charming, full of fire, imperfect man. So casting Louis was such a difficult task (but) such an exciting thing. He had to be this person that you felt the audience would root for. Someone who has a very strong spirit and someone who is soulful enough to love and respect Louis to understand the growth of the man.