No. It established that tyranny can be enforced at the cost of 600,000 lives for an uncertain amount of time.
The recent nonsense regarding the Confederate Battle Flag simply illustrates the tyrannical nature of the victors in that war.
No, it established that it's not smart to start a war with an entity that can whoop you. The South fired the first shot, they were the aggressors, and got their butt handed to them.