Who had the most profound effect on the issue of slavery in th?

The most profound effect on the issue of slavery in the United States was exerted by abolitionists like Frederick Douglass and Harriet Tubman, who raised awareness through their powerful narratives and activism. Additionally, President Abraham Lincoln's Emancipation Proclamation in 1863 was a pivotal moment, as it transformed the Civil War into a fight for freedom. The combined efforts of these individuals and events significantly shifted public perception and ultimately contributed to the abolition of slavery.