Definition: A dedicated opponent to slavery in the early 19th century America.
The abolitionist movement developed slowing in the early 1800s, but by the 1840s and 1850s it had a strong and very committed following. Prominent abolitionists included William Lloyd Garrison, who published an abolitionist newspaper, and the escaped slave Frederick Douglass.
The term comes from the word abolish, and particularly refers to those who wanted to abolish slavery.

