No, the south lost the Civil War, the War between the States, the War of the Southern Rebellion, or Jeff Davis' War. There was no War of Northern Agression.
To my knowledge, the Northern armies are the ones that initially invaded the South. If you and I are neighbors and you say I'm ugly but I come across the property line and start beating you up -- who do you think will be viewed as the aggressor?
Then, in keeping with Abe Lincoln's very own definitions, let's call it the "War of Northern Invasion and Coercion."
"The words ``coercion'' and ``invasion'' are in great use about these days. Suppose we were simply to try if we can, and ascertain what, is the meaning of these words. Let us get, if we can, the exact definitions of these words---not from dictionaries, but from the men who constantly repeat them---what things they mean to express by the words. What, then, is ``coercion''? What is ``invasion''? Would the marching of an army into South California, for instance, without the consent of her people, and in hostility against them, be coercion or invasion? I very frankly say, I think it would be invasion, and it would be coercion too, if the people of that country were forced to submit." - Abraham Lincoln, February 11, 1861