The physical setting of Narrative of the Life of Frederick Douglass is Maryland, the state where Douglass was born, a slave state, a border state, and where his days in bondage began and ended.
The immediate setting changes as the narrative progresses, from his original master, who sells him to cover up his illicit mixed blood offspring between himself and Douglass' mother, through a series of owners, and finally to a slavebreaker, Edward Covey, whose job it is to make a rebellious Douglass mind.
The other important setting is the world of a slave. That world where your family relations are torn from you and sold, or you are torn from them. Where cruelty is common and discipline harsh and swift. Douglass takes us there in this narrative. Any doubt readers of the time might have had about the evils of this institution had to be shattered by his gripping accounts of beatings, enslavement, and escape.