While obtaining my undergrad degree in History, I took at least four classes that touched on the Civil War. One was specifically on the war and Reconstruction. Another was specifically on the American South. None of my studies made more than a passing mention of the Confederate Home Guard.
From what I've read the purpose of the Home Guard was, ostensibly, to protect the home front from attack. In the movie, Jude Law's character, a deserter, lives in constant fear of capture by the guard as he tries to make his way home. The characters played by Nicole Kidman and Renee Zellweger, as well as others in their locality, are terrorized by a band of the Home Guard that executes not only deserters, but those that provide them aid. They seemingly act with impunity.
My questions:
How extreme a fictionalization is this? Do we have documented cases similar to what we see in the film? If so, did such groups face retribution after the war?
Also, as I understand it the Home Guard was officially part of the Confederate army. How would one get that assignment? Its members in the film are all of fighting age. Was anyone able to use it the way some used the National Guard during Vietnam, as a means of avoiding service on the front?
Though I have not seen the movie, I can tell you that the Confederate Home Guard relentlessly tracked down deserters. I'd recommend Stephanie McCurry's Confederate Reckoning, which recounts a few of the more horrific accounts, and is just a great book. I will summarize one here.
Col. Pike, of the Confederate Home Guard in North Carolina, pursued William Owens, leader of a deserter band. Pike interrogated Owens' wife, slapping her violently, using thumb clamps, suspending her, and torturing her. She eventually gave up her husband, who they probably executed on the spot. These kinds of events were not at all uncommon during the war.
Home Guards basically formed themselves from men who did not go off to war for one reason or another. A local wealthy planter who paid his way out of the draft might raise up a home guard regiment and fashion himself a colonel. They might also be a group of wounded soldiers who cannot fight in war any more, but wish to continue contributing to their cause. Others might be slave patrols with extended powers. There was not a lot of oversight or hierarchy, and given the chaotic state of Confederate government late in the war they were able to operate fairly independantly.