I intended to release each expansion to Command Combat: Civil War on the 150th anniversary of the year it represents. That means 1864 would be released this year. Alas, it has taken me a bit longer to put it together than I expected. This is partially because of the plethora of books I've been releasing, but it's also because 1864 is going to have an almost entirely new game in it. As it will be introducing campaigns into the game, there will be rules for playing large scale actions that involve entire theaters of war, and how to integrate them with miniatures games. So, as such, 1864 might be coming out early next year. But it must be finished by the middle of February, as I'm scheduled to show it at Strategicon in Los Angeles. So that will probably be the release event for it.
In the meantime, I will be posting elements of the expansion here between now and its release.