Excise was minimal.
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.