Here's another tid-bit which might be relevant if the folks saying Tennessee isn't true Southern are themselves backwards enough...
The Emancipation Proclamation wasn't actually meant to free the slaves. Lincoln was a racist who, in the Lincoln-Douglass debates said Blacks were physically inferior and should never be granted equal citizenship. The "Emancipation" Proclamation gave most of the Confederate States 100 days to rejoin the Union- and if they did they could keep their slaves. The EP, however, didn't apply to all slave states. Only Confederate slave states. What's more, it didn't apply to all Confederate slave states.
The slave states of Delaware, Maryland, Missouri and Kentucky never joined the Conferacy, and Lincoln & the EP left the slaves in those states- as well as the pro-slave territories- in bondage until well after the war. What's more, the EP specifically excepted the slaves in the Confederate state of TN (the home state of Andrew Johnson, Lincoln's VP).
Like Virginia, TN didn't join the CSA until the 2nd vote, after Lincoln had suspended Habeus Corpus, arrested the entire Maryland Legislature for daring to defy his order to not even discuss the succession of the early CSA states, and declared all State troops federalized whether they liked it- or it was legal- or not. Even then, 90K Tennesseans went North & 110K went South.
If you take all that into account, then obviously, from a certain can't-walk-without-dragging-knuckles concept of "Southern", most of TN has never fit.
Of course, we're talking people whose definition of "Southern" doesn't include opposable thumbs.