The American Civil War isn't called a "slave revolt" because it wasn't one. One country invaded another and freed the slaves of the invaded country for several very practical and tactical reasons. In relatively few instances did any slaves revolt against their masters. Some may have joined the invading army after leaving their masters, but the war was in no way a "slave revolt."

That being said, the disturbance in question was also in no way a "civil war" - which is a war in which one faction in a country tries to take control from the current ruling regime and replace that government with their own regime. So I guess if we play by the linguistic rules that allow it to be called the Civil War, we could call it a "slave revolt." Or an "open house," or a "bake sale," etc., etc.