How we cite our quotes: (Chapter.Paragraph)
Quote #1
Death, however, was neither simple nor lightly brushed aside when it struck home. Jethro frowned: he didn't like to think of his sister Mary's death, but some memory had been touched off as his thoughts wandered […] He had not forgotten though; he'd been only seven that winter of '59, but the memory of the tragedy would always be sharp and terrible in his mind. (1.54)
Mary's death leaves a lasting impression on Jethro, not only because it was his first real experience with death but also because she was his older sister. And while death, with all its causes, is always a bitter pill to swallow, the circumstances surrounding Mary's death are extra tragic since it was an accident that didn't have to occur.
Quote #2
He loved Walnut Hill in spite of the sadness of the place since Mary died. There had been no sadness for Jethro when only the little boys were there; these three had been imaginary playmates for him when he was younger.
[…]
Matt had watched Jethro's whereabouts more closely after that, and the boy realized that for some reason his father did not approve of his going up to play on Walnut Hill. After Mary was there, he stayed away through his own choice. He knew that Mary was dead, and it made a great deal of difference. (3.37-40)
Prior to Mary being up on Walnut Hill, it was almost sort of a playground for Jeth. And since it's basically a family cemetery, we can understand why Matt would be less than okay with that. But once Mary is buried there, Jeth considers it the sacred place it's meant to be. Personally knowing someone who dies makes all the difference. This idea comes back again when Jethro realizes that Jenny has memories of the little boys when he doesn't.
Quote #3
Jethro sat quietly watching his teacher's sober face. He thought of boys frozen under the snow at Donelson, he remembered that he had not loved Tom as he had Bill and Shadrach, and suddenly the warm, firelit room, the smell of food, the shelves of books, all wakened a feeling of guilt in his mind. (4.89)
Death of a loved one is hard enough no matter what, but these deaths at Donelson are different than the others that the war causes. The boys who froze to death did so because of their own foolishness in throwing away blankets and coats (4.26).