What did Fredrick Douglass do to convince northerners that slavery was wrong?

Frederick Douglass used his powerful oratory skills and personal narrative to convince Northerners of the immorality of slavery. By sharing his own experiences as a former enslaved person, he provided a compelling firsthand account of the brutality and dehumanization inherent in the institution. Douglass also engaged in public speaking, wrote articles, and published his autobiography, "Narrative of the Life of Frederick Douglass, an American Slave," which highlighted the injustices of slavery and appealed to the moral conscience of his audience. His eloquence and intellectual arguments helped shift public opinion against slavery in the North.