I heartily and without any reservation recommend reading a new biography of Alvin York that came out last year:
“Alvin York: A New Biography of the Hero of the Argonne” by Douglas V. Mastriano
http://kentuckypress.com/live/title_detail.php?titleid=3599#.VQNTdZV0w5s
And Mr. Mastriano discusses fully the Gary Cooper movie “Sergeant York” and the changes in the movie that were mostly approved by the real Sgt. York.
Rare qualities.