If anyone is interested in the American Civil War and games, you should love this.
Flying Squirrel Entertainment, the creators of Mount and Blade: Napoleonic Wars, are creating their stand-alone game called "Battle Cry of Freedom". It includes 500 multi-player battles, a complete destructible environment, historical representation of maps and tasks in the American Civil War, and much more. Here are some WIP screenshots:
This game is not free, but I think it's worth it once it is released. Here's the link to the website. http://www.flyingsquirrelent.eu/index.html