It's definitely not a Copperhead.
Joe, if you still live in TN, it's not a Gopher Snake because their natural habitat doesn't extend to TN.
If it was less than a foot and a half long, it was a juvenile Black Rat Snake (they turn almost completely black as they get older/larger):
If it was longer than that, it was probably a corn snake and your cell phone is just not picking up the orange-rust color that is normally in those splotches:
