Your answer is "Roger B. Taney." He was part of the supreme court, and believed that African Americans were inferior to other citizens in the united states, and, in fact, could not even be considered a citizen. He was the ultimate decider in the infamous Dred Scott vs. Stanford case.
Theodore Weld was an architect and abolitionist.
Harriet Beecher Stowe was an abolitionist author.
Sojourner Truth was an African American abolitionist and women's rights activist. As well as being African American, she was also born into slavery, so she is an obvious choice against slavery.
Hope this helps.
