Much of history (written by Yankees) taught since, teaches how brutal the Missouri Partisan Rangers were, they had to be to survive the onslaught carried out against them. All history (not written by supporters of the southron myth machine) will admit that the Kansas-Missouri border war started well before the outbreak of the rebellion and that the supporters of slavery were just as brutal as were the supporters of abolition. The first sack of Lawrence brought on the Pottowattomie Massacres which caused the massacre at Marias des Cygne which resulted in the Battle of Osawatomie and so forth and so on. And once the rebellion began the bloodshed on both sides got worse. So please don't try to paint Quantrell and Bloody Bill Anderson and their ilk as simple southern farmboys forced to commit acts against their will. They were blood thirsty psychotics who loved every minute of the misery and death that they caused. And there were more than a few just like them on the Union side.
The psychopath John Brown, Senator Lane & his red legs begat the Partisan rangers, and Bloody Bill had a bit of reason for being a bit off in the head after the unionists murdered his father & sister.
Face it, Missouri was our own Balkans war, for 10 years before, and 20 years after the civil war, neighbors were murdering neighbors with unrelenting hatred.
Some talk of the Hatfield's and the McCoys as being a war of the feud. Compared to Missouri, the Hatfield's and McCoys played make believe children's games.
Pure Hollywood, but check out this movie, it will give the drift of those hatreds.
http://www.contactmusic.com/new/film.nsf/reviews/ridewdevil