Douglass wrote this book to show people what slavery was like from the inside. He takes his readers into the mind of a child who is trying to understand what it means to be a slave. When Douglass tells us about his childhood, he emphasizes how little he understands about it. We discover the truth, with him, through his eyes.
Douglass is a little older now, and when he moves to Baltimore, his new master's wife starts to teach him to read. His master stops her, though, and this teaches Douglass an important lesson: reading must be pretty powerful, right? Douglass resolves not to let his education end just because he can't get any more lessons at home. He makes the streets his classroom, making friends with white children and eventually learning not only to read, but to write as well. But the most important lesson he's learned is about slavery, that a person can only be kept in slavery as long as he is kept in ignorance.
As Douglass gets older, he starts to do the one thing no slave is ever supposed to do: think for himself. So his master rents him out to Mr. Covey, a farmer with a reputation as a "slave-breaker." Covey works to beat Douglass into submission, and for the first six months it works. Douglass is too exhausted to think and too beaten physically to complain or fight back. He reaches the depths of despair when he looks out onto the Chesapeake Bay and sees the white sails of ships sailing free. Yet even while he questions (in a famous monolog) why he can't be free too, he starts to take courage and resolves to free himself, no matter what the obstacles may be.
Psychologists sometimes say that addicts have to reach "rock bottom" before they are ready to regain control of their lives. Perhaps because he reaches rock bottom with Covey, Douglass suddenly finds the strength to resist. Not long after the moment looking at the white sails on the Chesapeake Bay, he resolves that he would rather die than be beaten again. When he stands up to Covey and says so, he discovers something amazing: he doesn't die. And once he resolves to be free at any cost, things start to change. Defeating Covey doesn't make him free in a legal sense, of course, but standing up for himself makes him mentally free.
Having resolved to become free, Douglass must now find a way to actually do it. He no longer despairs -- in fact, he has complete faith that he'll find a way – but getting away from the slave states is still a complicated proposition. He doesn't know much about the North, and no one in the South will tell him anything. Even worse, there are slave masters watching his every move.
Douglass's first attempt to escape fails. He tries to lead a group of slaves to freedom by forging traveling passes for each of them (since no one expects a slave to know how to write). But the plan falls apart when one of the other slaves betrays the group to their masters, and Douglass is left back where he started.
It takes Douglass four years to do it, but he does eventually escape to freedom in the New York. But the story isn't over. Getting to the North isn't the end of his worries; if he were to be caught by his former master, he could be dragged back to the South and put in chains, and no law in the North could protect him. In fact, Douglass can't even tell us how exactly he escaped, since giving away that information might put the friends who helped him in danger. He eventually decides that New York is too close to the South and moves even farther, to Massachusetts.
At this point in Douglass's life, he faces a dilemma. He is becoming involved as a speaker and writer in anti-slavery politics, but the more famous he becomes, the more danger he is in. Talking about his life is a way of fighting slavery and helping others still caught in its trap. But the more he talks about himself, the more information he gives to his enemies and the more likely it is that he could be kidnapped back into slavery.
Eventually, years after the book was published, Douglass bought his freedom from his former master. Once he was legally free, he was out of danger. But when he first wrote the book that you're reading, he was still taking a great risk. In fact, taking that risk was a lot like standing up to Covey. Even if it meant risking everything he had, he would rather lose it all than be afraid.