I was doing some work on the Mexican-American War, and remarked to my coauthor, a Southern Boy, that the Mexicans refer to that war (in Spanish) as “The War of Northern Aggression.” He said, “Aren’t they all?”
Rather, the War of the Great Rebellion was begin by the southern insurrection.
The Mexican American war was begun by Mexico, when the US annexed Texas. Mexico lost that one about as fully as the slave power lost their insurrection, for much the same reason: The losing governments were so corrupt and evil that noone would help them.