Final answer:
Abolitionists were people who actively opposed slavery and advocated for its immediate and complete end.
Step-by-step explanation:
People who were actively against slavery were known as abolitionists. Abolitionists were individuals, both black and white, who advocated for the immediate and complete end of slavery in the United States. They used moral arguments and publicized the atrocities of slavery to create a society characterized by equality between Black and White people.