I'm reading Paddy Griffith, and he says something interesting in the introduction to Battle Tactics of the Civil War, to the effect that Stephen Crane & others talking about the Civil War in the Victorian generation introduced new & modern ways of thinking about war. In effect, Griffith argues that the sense in which the American Civil War was a "modern war", not in the tactical or strategic sense (he calls Sherman "medieval", which I think is rather a mistake, in that Sherman's attitudes are more Thirty Years War than War of the Roses) or even technological sense - but rather in a narrational sense. Even the organizational techniques of mass conscription was an innovation of the 1790s.
Griffith says that the introduction of mass literacy & mass authorship & the modern postal & newspaper culture transformed the way that Napoleonic carnage was interpreted & felt by a newly egalitarian culture. The impersonality and the sense of futile butchery was not, in this view, a novelty to the American Civil War, but rather a novelty to society, which was directly encountering the horrors of Napoleonic war via the torrent of letters and newspaper accounts flooding home from each new abbatoir.