Nonsense. It was the slave power's intransigence that brought the war. Their slavery was -guaranteed- by President Lincoln. It just wouldn't be allowed to expand.
"Abolitionists, in America, mean those who do not keep within the Constitution; the Republican party neither aim nor profess to aim at this object. ... If they have not taken arms against slavery, they have against its extension. And they know ... that this amounts to the same thing. The day when slavery can no longer extend itself, is the day of its doom. The slave owners know this, and it is the cause of their fury."
-- John Stuart Mill
Walt
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