pcr will tell you some of the reasons why what you've been told about the civil war is misleading at least, and in some ways deceptive. it was a war of succession and not a civil war to begin with, and slavery was a part of the reasons though not the largest and from there it depends on who you would have asked;

A “Civil War” Lesson for the Uneducated
Paul Craig Roberts
In response to my short essay on November 9 ( https://www.paulcraigroberts.org/2018/11/09/the-prevalence-of-myth-over-history/ ), a reader sent me a link to secession documents that implicated slavery, not the tariff, as the reason for Southern secession. It is typical for the uneducated to come across a document of which they have no understanding and to send it off with a rude “got you” note to one who does understand the document.
I have explained the Southern states secession from the union in long essays. See:
https://www.paulcraigroberts.org/2017/08/23/know-called-civil-war-not-slavery/ and
https://www.paulcraigroberts.org/2017/08/28/weaponization-history-journalism/ and https://www.paulcraigroberts.org/2017/09/18/whatever-happened-america/ and https://www.paulcraigroberts.org/2015/04/13/power-lies/ and https://www.paulcraigroberts.org/2017/08/21/trump-american-history-assassinated/ .
Once again:
When the Southern states seceded, they were concerned to do so legally or constitutionally under the Constitution so that the North could not legally claim that it was an act of rebellion and invade the Southern states. To make this case, the South needed to make a case that the North had broken the Consltitutional contract and that the South was seceding because the North had not kept to the Constitution..........https://www.paulcraigroberts.org/2018/11/13/a-civil-war-lesson-for-the-uneducated/