It is evil, but Lincoln, via the “Corwin Amendment,” supported its preservation in the states where it existed at the time of his inauguration.
So you think he started the war for what purpose?
Inaccurate. The Corwin Amendment merely made explicit the belief of almost everybody, including Lincoln, that Congress had no power to legislate on slavery within a state. Part of the amendment made it impossible to be itself amended by a future amendment. Something that is arguably unconstitutional.
Lincoln, who wasn't yet president, did not support the amendment, which would have been kind of pointless since the president has no role in the amendment process.
He merely said that if the amendment was desired by the country, he had no objection to it being made "unamendable." This was unobjectionable, since it merely made explicit what he believed the Constitution already said by implication.