I should mention, that this is the 1988 release/print as there seem to be several versions of this game dating back to the 60's. This is also seems to be the 125th anniversary edition you can find on BoardGameGeek.
I've not seen the Gettysburg, but others of the Smithsonian editions seemed fair departures from the original AH games. Guadalcanal in particular sticks in my mind as being almost a 180, given that the original 60's game was land warfare(mostly?), and the Smithsonian was about the naval battles.
I suspect this is closer to the original Gettysburg game by the looks of it.
Also, one or two didn't have AH precursors; as I recall. Mustangs was such.
Since this is a forum for figs, I didn't notice comments on stacking. Do you think this could use figs, ala Battle Cry? Probably Hair Roller units, though.
Doug