In the novel, Tom's back story really explains his extreme devotion to the Corleone family. His father was an alcoholic and his mother went blind. He was homeless and starving when Sonny brought him home to live with them, and sick with an eye infection. He was convinced that he would go blind like his mother, but the Corleones took him to a doctor that cured him.

He often had nightmares about being homeless and blind, and only the sound of Vito's voice when he woke up could soothe him.