Matrix Games is evidently getting ready to offer the soon-to-be-released
Gettysburg: The Tide Turns, by Shenandoah Studios (see:
http://www.matrixgames.com/products/635/details/Gettysburg:.The.Tide.Turns). The game is advertised as an intermediate, turn based, PBEM playable product featuring "an innovative, randomized turn system!" The game doesn't appear to be compatible with any Windows OS below Win7. Still, the game might prove to be a candidate for ACWGC sanction, as would WCS's
Brother Against Brother (see:
http://www.matrixgames.com/products/505/details/Brother.Against.Brother).