Hi d00d,
as far as i know there is "only" one map worked on, which is Sharpsburg/ Antietam and yes they are creating it based on historical battlefields as you can see on moddb http://www.moddb.com/games/war-of-rights/images. I have no idea what is planned for the future, but as you can see how large those maps are you can assume that it will take a lot of time creating more....personally i am looking forward to close quarter combat at Fredericksburg and storming little round top