Your false god said it was to "preserve the union."
You've probably seen this before:
"Both parties deprecated war; but one of them would make war rather than let the nation survive; and the other would accept war rather than let it perish. And the war came."
Walt
And in his usual fashion, The Lincoln got it completely backwards. The South sought a peaceful separation and urged repeatedly that peace be made. The North, and especially The Lincoln, would have none of it and instigated war. The North made war to ensure that its power survived, while the South accepted it to prevent self government from perishing.