Who is Lincoln Lloyd from Little Altars Everywhere and what is their importance?

Lincoln Lloyd is Chaney's hard-working younger brother. Many people believe Lincoln is retarded because he stutters. Big Shep Walker, however, knows better. When Lincoln is drafted, Chaney begs Shep to get the boy excused. He refuses because he thinks that being drafted into the army will be a great opportunity for Lincoln. Lincoln is eventually sent to Vietnam, where he is killed. Chaney eventually forgives Big Shep, he cannot forgive himself.