Marty is the protagonist, or main character, of the novel. He is an 11-year-old boy who lives with his parents and two younger sisters in a "four-room house with hills on three sides." Marty loves the woods and the meadows and the animals that inhabit the area. He takes his rifle out to shoot but "never shoot(s) at anything moving . . . never had the slightest wish." He can't eat rabbit that his father's killed because he can't stand the thought of the rabbit suffering, he encourages his sisters to release fireflies they capture and put in a jar, and he does all he can to protect a skinny, scared beagle that follows him home.
Marty is a dynamic character. He changes during the course of the novel due to his experiences and actions. Naylor narrates Shiloh in the first person, so we know how Marty changes because his thoughts and feelings are revealed. When the novel begins, the little beagle, that Marty names Shiloh, follows him home. Almost immediately, Marty falls in love with the dog. He is sure Shiloh came to him for help, and he intends to protect Shiloh from the abusive hands of Shiloh's owner, Judd Travers. When Marty goes with his Dad to take Shiloh back to Judd, Marty feels as though he has let Shiloh down, as though he has not protected Shiloh. He thinks about Shiloh night and day, trying to figure out how he can purchase the dog from Judd.
Within days, Shiloh shows up at Marty's house and Marty, determined to keep him, quickly builds a pen on the hill and keeps Shiloh's presence secret. As time passes, Marty experiences an inner conflict. He loves Shiloh and wants to protect the dog; however, he also loves his family and feels guilty about lying to them about where he goes and what he is doing with the leftover food from his dinner plate that he's giving to Shiloh. Marty learns from experience "that you can lie not only by what you say but what you don't say."
Marty lies to Judd about whether or not he has seen Shiloh in the yard (Shiloh has not been in the yard, he has been in the pen up the hill). Marty experiences a conflict with Judd because he wants Judd's dog and Judd wants his dog back. Marty also experiences a conflict with society — he doesn't understand laws that don't protect animals from mistreatment. Marty knows that he can't do anything about the laws in time to save Shiloh from Judd's abuse.
At the conclusion of the novel, Marty gains insight about why Judd is so mean, and he begins to treat Judd in a friendly manner. Marty keeps up his end of their bargain and realizes that "nothing is as simple as you guess . . ." He has matured and "opened [his] eyes some," understanding that everyone's approach to a problem or dilemma is different and his way may not have been the best, but it worked.
Dad (Ray Preston)
Marty's dad works hard at his job as a postal carrier. Family is important to Dad. Even though they don't have much money, they manage to send any extra money to his sister, Hettie, to help care for his ailing mother. Marty's father is a proud man who values truth and honesty. He understands the ways of the people who live in Tyler County. He respects other people and their privacy, he minds his own business, and he has "the sense to shut up" — qualities that he tries to impress upon Marty.
Marty's dad gets upset with Marty for speaking boldly to Judd Travers, but he seems to understand and is gentle with him. Dad always looks out for Marty. Knowing that Marty wants to find out how Shiloh is, Dad indirectly asks Judd questions about his dogs when he delivers Judd's mail. Marty is aware of Dad's consideration. Dad is perceptive; he notices that Marty is not acting like himself, and so he discusses Marty's behavior with Ma. Dad is concerned about Marty. Dad is also quite sensitive. When the German shepherd attacks Shiloh, Dad takes Shiloh to Doc Murphy rather than back to Judd. Dad never yells at Marty or punishes him for telling lies and hiding Shiloh. Instead, he doesn't say anything, forcing Marty to accept responsibility for his actions and tell the truth. Dad also agrees to let Shiloh stay with them until Shiloh's wounds have healed. When Shiloh is staying in the Prestons' kitchen, even Dad becomes attached to the little dog and can be seen petting Shiloh and letting Shiloh lick his plate clean. Dad is patient and forgiving, seeming to understand Marty's dilemma about Shiloh.
Ma (Lou Preston)
Marty's ma has ". . . a pretty face. Plain, but smooth." She takes care of the house and children. When she can get outside work to do at home, such as stuffing envelopes, she does that to help out with their bills. Ma is observant and intuitive. She seems to know just what Marty is thinking most of the time. Ma discovers that Marty is hiding Shiloh. She is perceptive and realizes that Marty might run away with Shiloh. She is adamant when she tells Marty never to run away from a problem. In spite of her better judgment (because she has never kept a secret from Dad), she agrees not to tell Dad about Shiloh until the next day. Of course, when the German shepherd attacks Shiloh, and Dad finds out that Ma has known that Marty has been hiding Shiloh, he is upset with her for not telling him.
Ma is a caring person. She quickly grows attached to Shiloh and even bakes a cake to celebrate the last day Marty has to work for Judd and Shiloh becomes their dog.
Judd Travers is a mean looking man who lives alone in a trailer not far from the Prestons. He has a "big round face, whiskers on his cheeks and chin where he hasn't shaved . . . tight little eyes . . . beneath big bushy brows." His teeth are stained from chewing tobacco and he has a noticeable belly. Judd reads Guns and Ammo and Shooting Times magazines. He shoots small game like rabbits and opossum and has been known to shoot deer out of season.
Judd is dishonest, crude, and insensitive. He abuses his dogs and thinks he is above the law. He tells Marty's father that the "law never told me before what I could do with my dogs, won't be tellin' me now." He talks about kicking his dogs and not feeding them when they've done something he dislikes.
Judd reveals to Marty that his father abused him as a child. Because no one ever felt sorry for him, he never felt sorry for anyone else. As a result of being abused, Judd is angry. He is unfamiliar with feelings related to kindness or friendliness. The closest Judd comes to showing any sensitivity at all is when he leaves a glass of water — with ice — for Marty when Marty is working for him. The last day Marty works for Judd, it is as though Judd really doesn't want to see Marty go because he will miss Marty's company. Marty paid attention to Judd and talked to him as though he mattered. Judd shows that when a person is treated with respect and someone pays attention to them, they can make changes. Underneath Judd's meanness, he shows that he can be decent. He acknowledges Shiloh by name and even gives Marty a collar for Shiloh.
David is Marty's best friend. His life is not at all like Marty's. He lives in a big, two-story house in Friendly. His mother is a teacher and his father works for the Tyler Star-News. His mother makes fancy lunches for David and Marty and sits down to eat with them. (When David visits Marty's house, Marty's mother gives them a bag lunch and they go up on the hill to eat.) David always has different toys to play with and lives a privileged life in comparison to Marty's life. In spite of the differences in the way the two boys live, David and Marty are best friends. They seem to enjoy each other's company and their differences seem to complement each other.