The story of Pudd'nhead Wilson starts out by introducing a man, of course, by the name of David Wilson. David moves to Dawson's Landing in Missouri to begin or, possibly, enhance his career as a lawyer. When he moves to town he says things that would be considered questionable by the townspeople such as claiming that he owns half of a dog. Because of this statement, the people think he is dumb but actually they just can't fathom his intelligence. They nickname him "Pudd'nhead" because they think he is not smart, or as smart as everyone else but really he is smarter than them all. They don't feel as though he is legitimate in his preferred field and cannot gain any clientele, so he gets involved in fingerprinting. David is the only fingerprinter in town, so the townspeople have no choice but to come to him.
Then Roxy is introduced; things start to get interesting when she comes in the picture. Roxy is a slave who is one-sixteenth black but looks like she is of white decent. She is the lady who gets pregnant, most likely by her master, and switches her and the master's son to avoid having her son sold away from her to another master. Her son was named Chambers but, since he was switched out, was called Tom. Because he is now living in the master's house and the master thinks that he is his real son, "Tom" lives the life of a white man and later becomes heir to an estate. The master's actual child, Tom, is called Chambers because he and everyone else thinks he is actually Roxy's son. Because of his status, he lives the life of a black man and is brought up in slavery. "Tom", as a result of being spoiled and constantly being taught that he was superior to black men, turns into a selfish and evil man. He ends up selling Roxy, his "mother", and killing Judge Driscoll who is his uncle on his father's side.
There are two performers named Angelo and Luigi who say they are Italian heirs of a nobleman. Once they get to Dawson's Landing, they go to live briefly in Widow Cooper's house. Pudd'nhead Wilson reads his palm Luigi condpfesses to killing a man who had attempted robbery on his family. The item they tried to steal was an Indian knife, and it turns out "Tom", actually Chambers, is the culprit and used it to kill Judge Driscoll. Luigi ends up being arrested by "Tom" who decides to duel him instead. No one was killed in the duel, but "Tom" tells his uncle that Luigi is an assassin and is not honorable enough to be worthy to duel him. He does this only to save his reputation. Later on, Pudd'nhead Wilson is elected mayor, and afterwards "Tom" murders the judge with the twins' knife because they are in dyer need of money.
"Tom" flees the scene after killing Judge Driscoll by disguising as a woman. The Italian twins heard Driscoll's shouts and run to help him. They were pretty much set up because they were standing over his body, and their knife was on the floor covered in blood. It was stolen and they had nothing to do with the crime but were in the wrong place at the wrong time. They were put on trial for murder, and Pudd'nhead Wilson, all thanks to his fingerprinting collection, reveals that "Tom" is responsible and that he is actually Chambers. "Tom" goes to jail and, because he was really a slave all along, sold to pay debts from the real Tom's father's estate. "Chambers" is revealed to be Tom and is placed back in his position as a white heir to the estate. The only bad thing is that he was raised as a black man and was not used to living the life he was "supposed" to. Pudd'nhead is mayor of Dawson's Landing and can now be a successful lawyer.
