Full emancipation, with no war, no destruction, and no casualties, was accomplished in Brazil only a few years later, in 1888, because even there it was no longer profitable.
In the U.S., there were about 3 million slaves on the eve of war. Their per capita value was less than $1,000 average. They could have been free via eminent domain compensable emancipation for about $3 billion.
Instead, Lincoln embarked on a war costing between $6 and $12 billion in direct spending and related costs, 600,000 in battlefield deaths, and leaving a quarter of the country devastated. His defenders point to his compensated emancipation effort, within the District of Columbia only, in 1862, but it largely failed because his buy-out price was only $300. He could have made it higher but chose not to.
I believe, but of course can't prove, that most slave-owners were, by 1860, smart enough to see the economic future of slaveholding and would have welcomed a buy-out. The South would not have been impoverished, Reconstruction would not have been needed, and the bitter recriminations which survive to the present day would not have arisen.
Buchanan is to be faulted, somewhat, for choosing not to address the coming problem, but that's what politicians do. For Lincoln, in my opinion, there is no excuse.
You'll find, in Thomas DiLorenzo's "The Real Lincoln" a more lengthy and detailed recitation of the above economic argument. What you won't find in it, or anywhere else, is any explanation of the standard military practice of the war, set-piece battlefields with infantry in parade-ground formation marching against massed rifle and artillery fire, ordered to such suicidal behavior by generals who mostly sat safely in their tents (Battles of First and Second Manassas) but occasionally led them and died as uselessly as they did (Nashville).
Pickett survived his charge at Gettysburg; his regiments and their commanders didn't. I've tried to learn, without success, why military leadership able to utilize, century-old Roger's Rangers and Marion's Swamp Fox tactics of maneuver-and-fire with cover-and concealment, chose not to use such approaches? No military historian or contemporary instructor will answer my inquiries. One excuse sometimes proffered is that conscripts would flee the battlefield if not tightly controlled, but of course most of the Civil War was fought by both sides with volunteers and not conscripts.
Former Vermonter Martin Harris lives in Tennessee.