Not so. The South had the cancer of slavery eating at its belly. The whole mountain region was supporting the North. A lot of southerners didn’t want to die for a bunch of rich landowners who sent slaves instead of sons. Choosing Richmond for the capital was a big mistake.
The North’s manufacturing capacity spelled doom for the Confederacy.
Possibly, but at that point in the war the North was losing and demoralized. A loss at Gettysburg may have pushed public sentiment over the edge in the North. Slavery was going to end soon, anyway, IMHO, but the state’s rights argument was lost forever.