The subject book by Thomas DiLorenzo brings home one point that is much worth the read. We are taught in school that "Lincoln saved the union" and he was "the great emancipator". Those two items are somewhat true, but vast oversimplifications.
The greatest insight of the book is that "the union" that was "saved" wasn't what used to be called "The United States". The cost of the civil war was that the idea of "rights moving from God to the people to the states to the federal government" was destroyed at gunpoint, and replaced with the idea that once a state, always a state, or we will deal out death until you get it right.
The right of secession is a MUST in a country where the rights come from the people! The America of our founders and of the Constitution they created would have allowed the South to secede peacefully. Lincoln could not, and in fact pushed the South to war with "The American Plan" -- 1). Central Banking 2) High Tariffs 3). Internal Improvements.
For the South, this meant that they paid all the tariffs and all the "improvements" (which were essentially payola for companies) ended up in the North.
As the author pointed out, slavery was ended peacefully all around the world, and prejudice against blacks was at least as strong and in many ways stronger in the north. Lincoln himself wanted to ship the blacks back to Africa and felt that the two races were never tended to coexist. Were the south to have seceded peacefully, it is quite likely that slavery would have been ended in a decade or two via compensation to owners or a scheme where the children of the slaves were freed on their 21st birthday. Having over 620K Americans die wasn't required to end slavery.
I was personally struck by some of the sentiment that I first experienced when we had some friends from southern Indiana that would have been just south of the Mason Dixon line. Going to public school in the north, the Civil War is cut and dried -- the North is just, the South is unjust, Lincoln is a hero, the war was the only way to end slavery, and everyone ought to be thankful that it was fought. Not so in the South. This book is a more academic look at the kinds of sentiments that many of the folks of the South still carry over 100 years since the war. Being on the losing side makes a difference.
In reading the book, one realizes how expensive the Civil War was not only in lives and treasure, but in the loss of liberty and autonomy of the states that may well have been an irrecoverable blow that will eventually completely destroy the liberty that the country was founded on.