Whatever the motives it was a huge failure of Lincoln's leadership to choose the path of death and destruction. The death of 600,000, wounds of many more, and the destruction of huge amounts of property wasn't necessary. Today we mourn the death of 10 in battle on a bad day. Then, they mourned the death of 10,000 in one battle in one day. Imagine that. When the slaves were "freed" it was without preparation leaving them poorly equipped to survive.
As a libertarian I find involuntary slavery repugnant. I find mass killing and destruction more so.