In the third or fourth grade I read three books I liked but I can’t remember the titles.
Book one was a fantasy/horror involving a preteen boy and his older sister moving in with a member of their extended family, possibly an aunt or grandmother. The family member’s house was near a Civil war battlefield. The siblings visit the battlefield one day and the boy meets the ghost of a cadet that died in a battle when he was about the preteen boy’s age. The boy befriends the ghost. The boy ends up having to help the ghost get out of this world or something like that. I remember that the ghost’s last name was MacDowell or something similar. I also remember that another family member of the sibling’s had just died and that may have involved the moving.
Book two was about a preteen girl and her younger brother running away and living in a museum. That’s all I remember.
Book three was about a boy that may have been mentally retarded, but I didn’t recognize it at the time I read the book. He was good at untieing knots and liked baseball. It may have been a series.
Thanks for the help.