As I admitted, I meant to say tariffs, not excise taxes as someone also noted.
As far as being “anachronistic”, I stand by my assertion, the war was over money much more than slavery. In fact, there would probably have been no shooting had the union simply let the states go or sought redress through the courts rather than pushing them into a shooting war by enforcing the tariff collections. It was only after 7 states seceeded that Lincoln called up an army (illegally) without congressional support which forced 4 more states to leave too.
Winners write the history books.
Losers write excuses explaining why they started their war and why they subsequently lost it.
It was a shooting war because Confederates shot at a federal fort and then followed up by invading Kentucky.