HiHi
Here are a couple of alternatives to the HSP Games, the 'Battleground' collection, John Tillers classic, 5 major Battles, played at regimental level; and 'Forge of Freedom' by Western Civilisation Software.
Forge of Freedom is a massive game and not for the faint-hearted, in it you will play either Davis or Lincoln (or choose to be King Artichoke XIII :-) ) and run the whole of the Civil War, Economics, Politics, Training, Logistics, Production, Supply, Navy etc. as well as fight the battles!
There are 2 battle systems, played at Brigade level; the detailed one gives you incredible control over how you move & fight your troops and is quite a steep learning curve (I found), but bloody rewarding when you get there.
If you have the time and the patience I strongly recommend FoF, but it ain't easy, and I'm only on Sergeant level! (It runs up another 5 or so levels I think)
Both games are playable as PBEM, and details can be found at Matrix games, here is the FoF link
http://www.west-civ.com/ForgeOfFreedom/FOF_Index.htm
Just do a search for ‘Battleground’ when you are there.
All the Best
Peter (The Other Kingmaker)