Decisive Battles of the American Civil War: Vol. 1 is an abandoned DOS strategy game set in North America, developed by SSG Strategic Studies Group, designed by Roger Keating, Malcolm Power, Ian Trout and published by SSG Strategic Studies Group in 1988.
It's available for download. Decisive Battles of the American Civil War: Vol. 1 is also part of the Decisive Battles of the American Civil War series.