What's the noun for abolitionist? Here's the word you're looking for.
abolition
The act of abolishing, or the state of being abolished; an annulling; abrogation; utter destruction; as, the abolition of slavery or the slave trade; the abolition of laws, decrees, ordinances, customs, taxes, debts, etc. [First attested around the early 16th century.]
(historical, often capitalised, Britain, US) The ending of the slave trade or of slavery. [First attested around the early 18th century.]
(historical, often capitalised, Australia) The ending of convict transportation. [First attested around the late 18th century.]
(obsolete) An amnesty; a putting out of memory. [Attested from the early 17th century to the early 19th century.]
“I suppose they did not think that, having been published before the deluge, it could have safely survived that world-wide calamity, the abolisher of all things.”
“He was the real abolisher of serfdom in Russia, as history will yet prove.”
“In the same passage as Jackson's inglorious fall, Stanford blesses President Lincoln, abolisher of slavery, and Baby Gauge, one of Francis's black blood brothers.”
abolitiondom
Abolitionists, specifiically the northern states during the US Civil War.