The States that made up the Confederacy:

[dalton99a]

38. Most Southerners say "Civil War"

A few avid defenders of those symbols talk of the War of Northern Aggression, and at least some people assume it is the South’s name for that war. And if not that, they think, white southerners surely call it the War between the States. Yet in a 1994 Southern Focus Poll, still the most extensive poll on attitudes toward the Civil War, when asked the war’s name only 6.5 percent of southerners answered War Between the States, and fewer than 1 percent offered War of Northern Aggression.

That name came into use only in the second half of the twentieth century. Before the 1950s, almost no southerners used War of Northern Aggression. It emerged out of white southern resentment of federal intervention in race relations during the civil rights era, and its use grew after that, encouraged by the neo-Confederate movement. As the Southern Focus Poll showed, however, even then relatively few southerners adopted it.[2]

War between the States has had a wider acceptance and a much longer history; the Focus Poll’s results reflected a decline in its usage. Surveys in the South Atlantic and Gulf South states, conducted by the Linguistic Atlas of the United States in the mid-twentieth century, found more southerners called it the War between the States, although still fewer than 25 percent. The polls also showed the upper-class and well-educated were the most likely to use it, which probably reflected the strength of the Lost Cause among the white South’s elite at that time.[3]

.. Even in the Southern Historical Society Papers, which began publication shortly after the war and which scholars consider the voice of the most intractable former Confederates, Civil War appeared twice as often as War Between the States.[5]

https://www.journalofthecivilwarera.org/2018/09/what-the-name-civil-war-tells-us-and-why-it-matters/