The prominent figure associated with the abolition of slavery in the United States is Frederick Douglass. Born into slavery, Douglass escaped and became a leading voice for the abolitionist movement. His powerful speeches and writings, including his autobiography, "Narrative of the Life of Frederick Douglass," highlighted the brutal realities of slavery while advocating for equality and justice. Douglass' work played a significant role in mobilizing public opinion against slavery and influenced key figures in the movement, such as William Lloyd Garrison and Harriet Tubman.