"The Discord That Follows" is an excellent example of this scenario
Well now. Thanks for the advertisement
It was about as big as it could have being actually, you are projecting 21th century Iraq onto post-Civil war South, the two were in completely difference situations. The south was in no position to wage massive guerrilla warfare.
Yeaaa. The South wasnt really ready for a longterm guerilla war. Especially since the US Civil War was one of the few that were conventional rather than partisan. Now during the Civil war some partisan warfare occurred, particularly in Missouri, but overall an army in the 1860's trained to fight a conventional war is really not all that effective in guerilla warfare. It would have caused trouble for the Union, but the guerillas wouldnt have made it far. Plus, many wanted to go home just like the Yankees.