Eben is a young boy living in the rural farming community of Sassafras Springs, Missouri, in the 1920s. He helps his father manage their farm but feels bored by his everyday routine. He possesses a curious mind and dreams of traveling to see famous global monuments. He accepts a challenge from his father to find local marvels, setting him on an exploratory path through his hometown.

Jeb is Eben's pragmatic best friend who belongs to a struggling farming family. As the oldest child, he takes on significant responsibility caring for his eight younger siblings and working the land. He lacks Eben's desire to travel the world, feeling a strong sense of duty to eventually take over his family's farm.

Aunt Pretty serves as Eben's maternal figure, having helped raise him after his mother passed away. She leads a quiet domestic life but possesses inner strength and resilience. She carries personal sorrow from her youth but remains highly supportive of Eben, knitting him clothes for his potential travels and encouraging his curiosity.

Pa is a hardworking, quiet farmer and a loving father to Eben. Despite grieving his late wife, he maintains a steady household and values his son's independence. He understands Eben's restlessness and cleverness, offering him a ticket to Colorado if the boy can find seven wonders in their own small town.

Mrs. Pritchard is Eben's Sunday school teacher, known for rarely inviting people into her home. She initially views Eben's quest as a waste of time and advises him to focus on his studies. However, she possesses a deeply personal artifact that she credits with saving her life during a severe childhood illness.

Cully is a tall, thin, socially marginalized man who lives alone in a disheveled shack. Often considered eccentric by the townspeople, he actually welcomes visitors with enthusiasm. He owns a bookcase that props up his roof, which he acquired after rescuing a mysterious rainmaker from a river.

Rae Ellen is a local girl whom Eben and other children usually avoid because she steals pies at school. She is persistent and eager to participate in Eben's quest, eventually showing him a miniature ship in a bottle that belonged to her uncle.

Calvin is a local farmer whose small plot of land produces unusually high yields. He is a self-taught musician who plays Christian hymns on a common handsaw. He views his musical ability as a divine gift that once protected his family's crops from a massive swarm of locusts.

Violet is described by Eben as the tallest and smartest girl in school. Following her father's death, her family became one of the poorest in Sassafras Springs. Despite her worn clothes and dirty hands from working the soil, she maintains a proud demeanor and invites Eben to see a special table at her home.

Eulie is Violet's mother, a widow who works hard to maintain their small farm. She is the custodian of a special table that once belonged to her mother, Rose-Ivy. She shares the local legend of how this table brought her parents together in a graveyard.

Coogie is a local boy with a penchant for mischief and storytelling. He invites Eben to see a "flying outhouse" and spins a wild tale about his father traveling the world in it. Though he enjoys playing pranks, he eventually decides to genuinely help Eben search for real wonders.

Mayor Peevey is the local civic leader in Sassafras Springs. After catching Eben and his friends in a minor theft, he uses the opportunity to teach the boy a lesson about forgiveness and accountability. He owns a special piece of woven cloth that he uses to share a moral story from his childhood.

Uncle Alf is a solitary widower who spends his time carving wood. He possesses a massive, intricate wooden carving of Sassafras Springs that captures the town's history. He learned his craft from a visiting artist in his youth and continues the work using wood from his grandmother's old loom.

Mrs. Saylor is one of the more affluent residents of Sassafras Springs. She is hospitable to the boys, showing them her expensive pearls and a brooch while offering them chocolates, though Eben ultimately decides her material wealth does not constitute a true wonder.

Mr. Saylor is Mrs. Saylor's husband. Unlike his wife, he is suspicious of Eben and Jeb's presence in his home, calling them rascals and prompting them to leave.

Old Emma is a blind woman from the town's past who was exceptionally skilled at weaving on her loom. She plays a central role in a local moral story regarding forgiveness and accountability.

Henry Upton is a historical figure in the town's lore, known as a rainmaker who moved to Garner County during a drought. He left his heavy bookcase behind after a dramatic event involving a flooded river.

Rose-Ivy is Eulie's mother, an independent woman who managed her own farm. Refusing to believe in local superstitions about ghosts, she investigated strange noises in the graveyard, which led to her meeting her future husband.

Tom is Eulie's father, a man who deeply mourned his first wife. His habit of eating dinner at her grave with a table sparked local rumors of a walking ghost.

Holt Nickerson is a man from the town's past whom Aunt Pretty wished to marry. Known for sleepwalking, he mounted his horse one night and vanished from Sassafras Springs entirely.

La Flame is a traveling artist who once visited Sassafras Springs offering to paint portraits. Recognizing young Uncle Alf's interest in carving, he taught the boy basic woodworking techniques before leaving town.

Uncle Dutch is Rae Ellen's uncle who once worked as a sailor on a ship called the S.S. Phantom of the Sea. He survived a terrible storm off the coast of Africa and recovered a ship in a bottle that he passed down to his niece.

Sal is Eben's loyal dog. He accompanies the young boy on his daily walks and his extensive search for the seven wonders throughout Sassafras Springs.

Junior is a schoolmate of Eben who attempts to participate in the search for wonders. He proudly shows Eben his collection of rotten eggs, though Eben determines they do not qualify as a true wonder.

Carrie is a local girl from Sassafras Springs who attends school with Eben. She tags along with her friend Maggie to lead the boys into the woods for a surprise.

Maggie is a schoolgirl who informs Eben that Coogie Jackson has a wonder to show him. She helps lead the boys into the woods to see the supposed marvel.

Albert is a local boy who spends time in the woods with Coogie Jackson. He helps Coogie execute a prank on Eben involving a supposedly magical outhouse.

Molly is Eben's cousin who lives in Colorado. Her location in the mountains represents Eben's primary goal and motivation for completing his father's challenge to find seven local wonders.

Lottie is another cousin of Eben and Aunt Pretty who resides in St. Louis. She offers to host Eben at her home, providing him with a new destination for his travels.

Cally is a childhood friend of Aunt Pretty who moved away long ago. She gifted Aunt Pretty a set of clothespin dolls that remain a cherished personal wonder.