Lawrence Keitt, speaking in the South Carolina secession convention, said, "Our people have come to this on the question of slavery. I am willing, in that address to rest it upon that question. I think it is the great central point from which we are now proceeding, and I am not willing to divert the public attention from it."
Lawrence Keitt was speaking for himself, not for every Confederate in the south.
To opine that West Virginia succeeded from the Confederacy and join the union to protect the freedom of black folks is almost humourous.
The Civil War was not a one-issue war, though we usually remember it as such.
Reminds me of the Simpsons episode where Apu was taking his citizenship exam. The questioner asked "What caused the Civil War".
Apu said "Well, sir, there were many causes of the Civil War, and he went on to rattle off 5 or 6 reasons when the questioner stopped him".
"Just say Slavery" the questioner said.
"Slavery it is!" said Apu.
And he got his citizenship.
Granted it's a silly cartoon, but sometime fiction and life converge in the strangest ways.
No one ever says that.
Walt