Set in the 1860s, the novel is about a lively eleven-year-old tomboy named Caroline Augusta Woodlawn, nicknamed "Caddie", living in the area of Dunnville, Wisconsin. As a young girl, she made the journey there from Boston with her family, one that nearly cost her life. Sickly and weak, she is allowed to run wild with her brothers, Tom and Warren, to regain her health. They spend much of their time exploring the woods and rivers that surround their farm. The book opens with Caddie being late for dinner after an excursion to visit the local Indian tribe, embarrassing her mother with her antics. She, undaunted, spends the next year having a string of adventures and scares. From a midnight ride through the forest to warn her friend, "Indian John", that the settlers are planning an attack, to a prairie fire that brings out the best in Obediah, the school bully, to a life-threatening fall through a lake while ice skating, her life is far from boring. Things come to a head when "perfect" Cousin Annabelle from Boston arrives for a visit, and Caddie is forced to confront her future. Tom and Warren, always a part of her adventures, come along for the journey. This story is full of practical jokes and touching moments, like the long journey home of Nero, a beloved pet dog that was taken by Caddie's uncle to be "educated". It tells the story of a family's existence on the frontier during the and offers insights into how life was lived in a small Wisconsin village where fear of local Indians was a reality, and life and death situations arose with frightening regularity. The sequel, Magical Melons (1939), continues the story of Caddie Woodlawn