If you want to be technically correct, it was not a civil war at all. A civil war is one between two parties attempting to gain control over one entity not one in which one party forces the other to not assert its independence.
It was a rebellion.
I agree with you, but that is the name it is most commonly known by, so I use it just to avoid having an argument over the term applied.
It is more accurately described as a War of oppression against the Independence of the Southern states.
Then as now, the Liberals try to manipulate the words to support their political agenda.