The story begins with the introduction of the narrator, Huckleberry Finn. Adopted by the Widow Douglas and Miss Watson, Huck quickly becomes dissatisfied with his new life and runs away to join a band of robbers with his friends. Soon after the band falls apart, Huck finds that his father, formally the town drunk, has returned. When kidnapped by his father and taken to a log cabin, Huck decides to escape, faking his own death and taking a canoe to Jackson's Island. On the island, Huck meets Jim, one of Miss Watson's escape slaves. When Huck is informed that Jim is a suspect in his murder, he and Jim leave Jackson's Island on a large raft, floating downstream at night and hiding out during the day.
Huck and Jim become very close friends. Their goal is to reach Cairo where they plan to take a steamship up the Ohio into the free states. When traveling through dense fog, Huck and Jim realize that they have passed Cairo. When their raft is hit by a steamboat, Huck swims ashore where he is invited to live with a family called the Grangerfords. After a family feud leaves all of the men in the family dead, Huck leaves to find Jim. Once back on the river, Huck and Jim encounter two men named the Duke and the King. These two men carry out a series of scams which gain them a good sum of money. The Duke and the King later sell Jim into slavery. Huck tries to rescue him, but it is not until the townspeople are informed that Jim's former owner has passed away, freeing Jim in her will, that Jim is released. Huck concludes the story by stating that he would never have undertaken the book had he known it would take so long to write it. .
There are two different angles that can be taken when reading the book. One is that of so many who find a problem with the racist content of the book. The word nigger is used as common, informal speech through out the story. This may be seen as racist by today's standards.