Who was talking about Lincoln? From the Northern standpoint it was never about slavery, merely combatting the rebellion and preserving the Union. On the southern side, however, defense of the institution of slavery was the prime motivation for the southern rebellion, and remained so until the very end. So while the Lincoln Administration 'took slavery out of the picture, as you say, the Davis regime did not.
[G] Explain why Southern independence was so bad...
[NS] Slavery this, slavery that, on and on...
[G] Slavery was not cause according to Lincoln (others)
[NS] Who's talking about Lincoln?
Bingo. Notice the concerted efforts by the usual set of suspects, trying change the topic of this thread to one more to their liking? Its a bit like listening to spare change circulate in a clothes dryer (repetitious, annoying, and ultimately not worth very much).
Cheers