[aculeus]

Civil War is an oxymoron.

BTTT

[aliquando]

How about “The War of Northern Aggression”?

[ExSoldier]

Civil War is an oxymoron.

It's the most common description but not necessarily the most accurate.

Many folks refer to this conflict as the War Between the States, or from the north: The War of Rebellion. Southerners with deep roots call this The War of NAWthun Aggression or more passionately: The recent unpleasantness.