If we are true to the English language and its usage, what is referred to as the American Revolution was in reality a civil war as opposing sides fought for control of the governance of the American Colonies. The 1861-1865 war was not a civil war as several Southern States had withdrawn from their voluntary political compact with other States, and formed their own voluntary Union. The South, then, had no interest in governing the North and truly fought in self-defense; the North, then, truly fought the war for conquest.
Bernhard Thuersam, www.Circa1865.com
“Matthew Forney Steele in his 1951 American Campaigns points out that the American Civil War was unusual for a civil war in having a purely sectional bias. Allegiance in this civil war was decided by one’s geographic location rather than class, religion, political allegiance, ethnicity or other factors that usually set the battling factions in a civil war apart from each other. This meant, in practical terms, that in the American Civil War the sides fought not among themselves but arrayed against each other.
The Southern Confederacy’s objective was simply to be left alone. The Union’s determination was to deny them that forbearance. Thus, an “invasion” of the Southern portion of the country, in Abraham Lincoln’s blandly legal phraseology, to “subdue combinations too powerful to be suppressed by the ordinary course of judicial proceedings,” became the war’s inevitable strategy.”
(Maps and Mapmakers of the Civil War, Earl B. McElfresh, H.N. Abrams Publishers, 1990, excerpt, pg. 20)