Trump isn't display of ignorance over why the war started. He gets roasted for wondering why things couldn't have turned out differently? What a dumb fucking article.
"People don't realize, you know, the Civil War, if you think about it, why? [...] People don't ask that question, but why was there the Civil War? Why could that one not have been worked out?"
Aside from making up a fake story about the dead Andrew Jackson responding to the Civil War, he's also being roasted for this attitude he does a lot, where he assumes that because
he doesn't know something,
nobody does (see: nobody knew healthcare would be this complicated). People don't ask the question of why there was the Civil War? Pretty sure there are entire fields filled with historians that study that very question their entire lives.