Who was the abolitionist that advised Lincoln to end slavery?

The abolitionist who notably advised President Abraham Lincoln to end slavery was Frederick Douglass. A former enslaved person himself, Douglass became a prominent advocate for emancipation and equal rights. He met with Lincoln several times, urging him to take a strong stance against slavery and to enlist Black soldiers in the Union Army. His influence and activism played a significant role in shaping public opinion and policy regarding emancipation during the Civil War.