The Upper South was never religious in nature like the Deep South was. There were founded under different circumstances. The Upper South was founded under an Anglican England. The kings who founded the the colonies that comprise of Tennessee, the Carolinas, parts of Virginia were Anglican, a lot of whom came from southern England (and as we know Anglicanism is Catholic). The Deep South was founded on the other hand under a Lutheran Britain (being King George II was king when Georgia was colonized). Most of the murders, lynchings and even conquest that happened happened by Deep South politicians (Andrew Jackson, for instance). Today the Deep South states has a stricter caste system socially than the Upper States, which is more laid back. The land of Hannah Montana really is friendly and they listen to you, unlike certain white folks in Georgia, Alabama and Mississippi who will threaten you with death. But then again, California is more like the Deep South than those Upper South states, so.
I am born and raised in the South, and have to say that I think racism was more than just a Deep South concept. Instead, I would argue that racism was pretty rampant throughout the existing states for over 100 years. However, I think that the reason we can suggest that it was a Deep Southern concept is because the deep south tended to be where the major plantations were. South Carolina and further South seems to be where the bulk of the slave population was. As a result, this led to radical racial hostility, as opposed to the justified racial tensions that existed further North. So in essence, I believe that racism honestly existed, and still exists, everywhere in the United States; but it was arguably the most intense down South in plantation land.