The U.S. Government spent over $1 billion dollars from 1860-1865 to wage the war that subdued the Southern states and ended slavery. That's 1865 dollars. And that doesn't include money spent by Confederate states.
In 1860, there were roughly 385,000 slave owners in the United States-- including states that did not secede.
Though slavery existed in many nations of the Western Hemisphere, every such nation ended slavery in the time between 1794 and 1888. Only two nations accomplished this via war: Haiti and the U.S.
So, being bored waiting for daughters' dance classes to end, I wondered how much would each slaveholder have gotten (in today's dollars) if the government simply bought the freedom of the slaves? The answer is, it depends on how you calculate it-- but the amount is significant.
This site discusses the various ways in which the value of a dollar may be calculated between different years; the manner of calculating this varies. You can read it yourself; I am no economist.
According to the site, an 1865 dollar would be worth between $12.80 and $1,680.00 today. Thus, the U.S. Government spent between $12,800,000,000.00 (12.8 billion) and $1,680,000,000,000.00 (1.68 trillion) in today's dollars.
Dividing the sums equally among the number of slave owners (yes, there are other ways to to this), each slaveholder would have gotten the following amount of today's dollars to free their slaves:
Simple cost of living: $38,480
Labor value: $319,800 (using unskilled labor value)
Labor value: $647,400 (using production level worker value)
Economic power: $4,368,000
Just a thought exercise, of course, though several countries did just that-- they compensated the former owners to secure the greater moral and societal good of ending the abhorrent practice of slavery. Again, the Lincoln administration spent from $12.8 billion to $1.68 trillion on the war. What if he just signed checks instead?
Oh, and in case you were wondering, 620,000 soldiers died in the war, and an undetermined number of civilians.