Meaning the only issue that matters in the context of the time. You see, since the Union condoned slavery in the South while it ruled there, and since it condoned it in the North all throughout the War, the North has no moral leg to stand on vis a vis the issue of slavery. It is an equally bad player.
Given that it was equally bad, the weighing of the issue must move on to the more serious principle of rebellion against our founding document, the Declaration of Independence.
I want to focus on this because THIS is where our current freedoms were lost. This blatant violation of the founding principles of this nation was the act from which much of our successive misery and abuses has flown.
I recognize that Slavery wasn't the reason the North Invaded the South. I recognize that it is a red herring and emotional bludgeon for which weak emotional minds always reach when they can't address the larger crises of the war.
That be you, and no, I don't want to focus on your "Look! Squirrel!" arguments.
But it's impossible to separate those issues. If I understand you correctly, then announcing that I'm now a foreign country because I want to, say, kill all the left-handers, is just as fine a reason as any, and opposing by force such an announcement is somehow more evil than breaking up the United States in order to murder left-handers.