Yes it was.
There is no constitutional right to secede,
There is, but for a better understanding, see "Declaration of Independence."
enslaving an entire race made a mockery of our stated intention to be a nation of free people,
The people didn't really care about that until the South decided to leave with their money. Also, the North was still keeping slaves as well.
of all races and the Confederacy opened hostilities by firing on Ft. Sumter.
Lincoln initiated hostilities by sending a fleet of warships and giving them orders to attack the Confederates.
And that's if you ignore the fact that Major Anderson initiated hostilities by seizing unfinished Fort Sumter in the dead of night while people were sleeping.
I've been down this road with you a hundred times, you Asperbergers ridden boob and yet you cling to YOUR version of history.
The South sought to preserve slavery as it's means of an economy and opening fire on Ft. Sumter ultimately led to the defeat of the Confederacy.
That is what happened to it as a result of it's ill fated, moronic idea to go to war. It just pisses you off to end because your precious CSA lost the war it started and you're steamed because your version of history is wrong.