Wrong. The War was not primarily about slavery. If it had been they would have simply let the states go their own way. They did not.
No sane person today defends slavery. At the time, there were many southerners who hated it. But slavery still exists today, but it is less obvious, and still very damaging. It is redefined. Now it is the Federal Government who wishes to make slaves of us all.
The south was defeated. But never subjected. Those echoes still reverberate in Texas. Texans will not quietly become slaves to the nanny state this time either.
Free Men need not ask permission.
If you think that the Civil War was not about slavery, you need to read the secession declarations adopted by the various states. They make it quite clear that they were fighting for slavery.
Of course it was about slavery. Every other consideration ever mentioned was adjunctive to the practice.