In a nutshell:
1. The North was unable to win the War until Grant and Sherman intentionally adopted the strategy of attacking, burning, looting and murdering civilian homes, farms and personnel. Under the laws of both then and now, these were actually War crimes, punishable by death. At Sherman's instruction, Sheridan (with Custer's help) started at the northernmost top of the Shenandoah Valley, and traveled down it for 200 miles, cutting a 25 mile wide swath, burning, looting and killing everything in his path, including houses, farms, cattle, and crops. (He laughed about it later, saying that if a crow flew over the Valley, he would have to bring his own lunch, because his troops had destroyed absolutely everything.) Sherman, in turn, performed his march to the sea, cutting a 50 mile wide swath, for 200 miles or more, across East Tennessee and Georgia, again burning, looting, pillaging and butchering every civilian target in his path. Of course, after the War, there were no trials or accountability for this. They were regarded as heroes by the North, and were later sent to Kansas and other parts of the West to employ the same strategy for exterminating the Indian tribes.
Not since the Revolutionary War had any people in the America been subjected to this type of barbarism.
2. For more than a decade after the War, the entire South was forcefully occupied by Federal Troops. Most people today in the North don't even know this. There was virtually martial law in the South for all of that time, and white male ex-Confederates were a favorite target.
3. My father is 89 years old, and still a practicing doctor. He recalls seeing as a child the very old Confederate War veterans limping in parades in Richmond. The farm were he was born, still held in our family, outside of Richmond (near Short Pump, Virginia) was occupied by Federal Cavalry during the War. His grandfather constantly told him about the atrocities, and he passed the stories along to us as children.
4. And finally, due to cultural differences, most Northerners, particularly the tens of millions of them from urban New York and New Jersey, are rude, obnoxious, tasteless people, who continually uphold an "air of superiority" in discussing and dealing with the South, despite the fact that their own cities are stinking sewers. Moreover, they appear to have no appreciation or understanding of the outdoors, firearms or hunting. (Their idea of an outdoor experience is putting on an NBA Jersey and going to a game at Madison Square Gardens.)
5. Happily, the South now has its revenge. The industrialized cities of the North are now bankrupt and rotting, from Ithaca, to Pittsburgh, to Gary, to Detroit. The vast majority of all new auto and other manufacturing companies are now built in the South, particularly the Mid-South (Tennessee, Arkansas, northern Mississippi). Duke University has now surpassed Harvard as the penultimate research medical center in the U.S., including new medical discoveries. The vast majority of population and building growth in the last 25 years has been in the South, particularly the Sunbelt, as more and more companies have discovered how badly the North (it's people, climate, taxes, and cities) really suck.
Any other questions? :-)
Mannyrock