When Douglass wrote this book in 1845, slavery was still legal in much of the United States. He became a public speaker and writer to try to stop it. He believed that if he showed people what slavery was really like, they would understand why it needed to be abolished. And who better than a former slave to tell the truth about slavery? So even though he wants to tell us his personal story, he never forgets the larger goal of abolishing slavery.
Douglass's Narrative was an instant success, selling over 35 thousand copies in the U.S. and Europe, and was quickly translated into both French and German. But can a piece with a political agenda also be great art? Douglass's book isn't a novel or a poem, and he tries to keep the language simple and clear (at least by the standards of his day), so it can seem like there isn't much to it.
But Douglass would eventually become the best-known abolitionist in the country (and the most famous black American of his era) because he managed to do so much more than just write a description of slavery. Instead of just arguing against slavery, Douglass asks some hard philosophical questions about what freedom really is.
Douglass wants to show us that he made himself free. Freedom isn't something that's given to us; it's something we each have to find for ourselves. And although Douglass had it a lot harder than most of us ever will, we each have something to learn from his perseverance and courage in search of his own freedom, and his refusal to rest before finding it.
Try to put some of this in your own words, don't copy it word for word because some of this was copied. I couldn't find some ideas for why he wrote this, so I looked some of it up.
I hope this helps, hope you have a great day, and hope it's 150 words lol. c;