Some key figures who played significant roles in the movement to abolish slavery include:
1) William Wilberforce: A British member of Parliament and a leader of the abolitionist movement in the United Kingdom.
2) Frederick Douglass: A prominent African-American abolitionist, orator, writer, and statesman.
3) Harriet Tubman: An African-American woman who escaped slavery to become a "conductor" on the Underground Railroad, helping other enslaved people escape to freedom.
4) Sojourner Truth: An African-American abolitionist and women's rights activist who delivered the famous speech "Ain't I a Woman?"
5) John Brown: A white abolitionist who led an armed raid on the federal armory at Harpers Ferry, Virginia, in an attempt to spark a slave rebellion.
6) Abraham Lincoln: The 16th President of the United States, who issued the Emancipation Proclamation, freeing enslaved people in the Confederate states during the American Civil War.
These are just a few examples of the many people who played essential roles in the fight against slavery. The abolition of slavery was a long and challenging struggle, and it was ultimately the result of the collective efforts of a diverse group of individuals, organizations, and movements.