The Tragedy of Pudd'nhead Wilson

Pudd'nhead Wilson (1894) is a novel by American writer Mark Twain. Its central intrigue revolves around two boys-one, born into slavery, with 1/32 black ancestry; the other, white, born to be the master of the house. The two boys, who look similar, are switched at infancy. Each grows into the other's social role.
The story was serialized in The Century Magazine (1893-4), before being published as a novel in 1894.
The setting is the fictional Missouri frontier town of Dawson's Landing on the banks of the Mississippi River in the first half of the 19th century. David Wilson, a young lawyer, moves to town, and a clever remark of his is misunderstood, which causes locals to brand him a "pudd'nhead" (nitwit). His hobby of collecting fingerprints does not raise his standing in the eyes of the townsfolk, who consider him to be eccentric and do not frequent his law practice.
"Pudd'nhead" Wilson is left in the background as the focus shifts to the slave Roxy, her son, and the family they serve. Roxy is one-sixteenth black and majority white, and her son Valet de Chambre (referred to as "Chambers") is 1/32 black. Roxy is principally charged with caring for her inattentive master's infant son Tom Driscoll, who is the same age as her own son. After fellow slaves are caught stealing and are nearly sold "down the river" to a master in the Deep South, Roxy fears for her son and herself. She considers killing her boy and herself, but decides to switch Chambers and Tom in their cribs to give her son a life of freedom and privilege.
The narrative moves forward two decades. Tom Driscoll (formerly Valet de Chambre), has been raised to believe that he is white and has become a spoiled aristocrat. He is a selfish and dissolute young man. Tom's father has died and granted Roxy her freedom in his will. She worked for a time on river boats, and saved money for her retirement. When she finally is able to retire, she discovers that her bank has failed and all of her savings are gone.