Hmm... it's probably wrong, but could it possibly be Entrex Software's Civil War game? I didn't have that one, but did have their American Revolution and Hannibal's Heroes games back in the mid '90s; I remembering both being awful. And yeah, I got a second one anyway. Wish I'd found a better historical-themed game instead.

Most of the Entrex games seem to be really hard to find any information about on the internet -- Civil War, American Revolution, and Hannibal's Heroes all aren't in either GameFAQs or Mobygames, for example -- but they do exist... I found a site with shareware or demo versions of them too: http://www.freeinfosociety.com/media.php?id=5407 (according to the page it's a demo. Haven't tried it.)