Slavery. It's one of those things that's so bad it's almost impossible to comprehend…even as it existed as a very real-deal (and supremely evil) economic system.

Free people living in the 19th century were aware of the evils of slavery. Whether it was firsthand on a plantation or through stories in newspapers and books, it was an ever-present theme throughout society. But without hearing about it in detail, slavery was so massive an atrocity that it was hard to take in.

Enter Frederick Douglass. The story of one man's journey from slavery to freedom, told in his own voice, was a super powerful thing. Frederick Douglass' first autobiography couldn't help but stir the hearts of the men and women who read it. His personal story connected with people, and the success of his book and subsequent speeches allowed the abolitionist cause to flourish.