No it wasn't. War was by no reasonable means a NECESSARY consequence of secession. It was a necessary consequence of beligerent military provocation, the expansion and exacerbation of military provocation, and the refusal of the provocateur to utilize ANY other means of resolution beyond war. Lincoln fit all three of those things.
"When I read [John Stuart] Mill I am always reminded of Oliver Wendell Holmes's words to the katydid: 'Thou sayst an undisputed thing in such a solemn way.'" - Lysander Spooner
It was if free men were to show they could govern themselves.
Walt
Then you agree that the slave power tried to break the Union to protect slavery.
Walt