I don't think it was romanticized at all and showed plenty of horror in the pictures of hoards of dead soldiers piled all over each other. I also doubt very seriously that the south was 'on the verge' of breaking away from slavery.' Growing up in the 50's and 60's here you would think that people still wanted slavery even then. It may have happened eventually, but to say 'on the verge' is something of an exaggeration. Slavery might as well have been abolished with a 5 year plan because that was the end result of the war, anyway. They also described the horror of the prisons, surgeries and disease that killed so many. Though even in tone, the descriptions given were plenty horrible, too. I think it made a good point that the war was only fought on the battlefield in fits and starts, but that people also had living to do without being in military service. Pretty complete picture I'd say.
Oh, and other causes of the Civil War. Yes, there were other causes like 'State's Right's' but these pertained to the State's Rights to slavery, in both the South and in new states on the western frontier.