One Man’s Reply to "That 1861-1865 war: What would you call it?"
The most-to-the-point name is "The War for Southern Independence" with "The War of 1861" a close second.
Except for the outcome, it was an exact parallel of the American War for Independence (1776-1781), with the United States of America playing the role played by Great Britain, and the Confederate States of America playing the part of the thirteen States.
It was not a civil war because it did not involve two or more factions battling over who would rule the entire nation. The seceded States wanted their independence; the remainder did not want to grant that independence (just as Britain did not want to grant independence to the thirteen States in 1776, the Spanish Empire to Mexico in 1818, or Mexico to Texas in 1836).
It was not a war between States because it did not pit Massachusetts against Alabama, or Maine against Georgia, or Indiana against Texas, or any State against another State. It pitted the United States of America against the Confederate States of America.
Clifton Palmer McLendon