The year is 1830 in Dawson's Landing, Missouri, a flower-filled town of modest homes and well-tended lawns on the banks of the Mississippi River. The town is "a slaveholding town, with a rich, slave-worked grain and pork country back of it ... sleepy and comfortable and contented" (7) and moderately religious. The river is the town's only exposure to the outside world, bringing people, goods, news, and the slave trade to Dawson's Landing, and providing a way for the townspeople to travel to and from St. Louis, the nearest city.

David Wilson, a young lawyer from New York, moves to Dawson's Landing. He is speaking with a few of the locals when, in the course of complaining about a barking dog, he makes a sarcastic remark about wanting to own half of the dog. Whether the remark is a reference to the biblical King Solomon's decision to divide a baby, or Wilson simply wanting the barking half of the dog in order to quiet it, the townspeople fail to recognize the sarcasm and take Wilson for a fool, labeling him a "pudd'nhead." This reputation follows Wilson until the end of the novel, when his strange habit of fingerprinting the residents of Dawson's Landing solves a mystery.