Short answer: if it had simply been a matter of morality Lincoln would have said so and acted accordingly.
Slightly longer response: This tentacle of the overall debate comes courtesy of jeffersondem who routinely hoists (foists?!) the canard, “...we can forever dismiss the notion that Lincoln and the North fought for the high moral principle of “freeing the slaves.”” or the startlingly insipid “Even after secession, the United States remained the most powerful slave nation in North America, perhaps the world.” or my “favorite”: “If the South was fighting for slavery, who was fighting against slavery?”
No matter how many times he is corrected and educated, he persists with these red herrings.
Lincoln had a duty and responsibility to defend and preserve the Union. At a point in the war he determined that freeing slaves in occupied areas was a priority. That there was an element of morality attached to his acts does not diminish the legitimacy or urgency of his actions.
“At a point in the war he (Lincoln) determined that freeing slaves in occupied areas was a priority.”
Apparently that is when the magic happened. The war took on a high moral purpose: as He died to make men holy, let us die to make men free.
President Lincoln announced slavery in the Confederate States had become ungodly, but that slavery in the United States would remain godly.
Therefore, troops from the Union slave state of Delaware fought in the Confederate slave state of North Carolina “to free the slaves.”
Troops from the Union slave state of West Virginia fought in the Confederate slave state of Virginia “to free the slaves.”
Troops from the Union slave state of Maryland fought in the Confederate slave state of South Carolina “to free the slaves.”
Troops from the Union slave state of Kentucky fought in the Confederate slave state of Tennessee “to free the slaves.”
And so forth and so on.
Brother Bull Snipe: “Yes, the United States (after secession) was the most powerful slave holding nation in North America with about 430,000 slaves.”
And so, critic answers critic.
My comments were general in nature, not specific to this thread (or any individual ;^). FWIW, the topic of antebellum 'States rights' was near & dear to my heart, during the early 2000's (IIRC, you & I threw some zingers back & forth during that period ;^). I can't remember the number of times I saw government actions defended, simply because someone thought they were moral, or the number of times I got hammered as a "slaver", "slavocrat", etc. And, in all honesty, I would hammer right back (sorry that you were likely on the receiving end of some of that).
Fast forward to 2019. The examples I listed ('Obama-Care', etc.) are 20th or 21st century issues; many current political proposals seem to be promoted on the basis of morality, with no thought whatsoever regarding the actual 'law of the land'. Government power seems to be 'available' any time it's required, via implication or judicial opinion, even for Republican proposals. And some current issues may be similar to points of contention from the early-mid 1800's.
How do I look at current events? If some issue pops up, do I just automatically support it (or oppose it?) based on gut-level feelings, or some previous moral judgement I made regarding similar historical events? Or do I make some (potentially difficult) decision(s) based on 'the law of the land', or a different moral evaluation?
We could easily face multiple "sanctuary State" issues over the next few years. Based on a previous judgement that "nullification" is wrong (as per 1830's South Carolina), do I also oppose some future "2nd Amendment sanctuary State"? Flip side of the coin: if I thought "nullification" circa 1832 was justifiable, do I offer knee-jerk support to California as a "sanctuary State" for illegals? The NRA was recently designated a "domestic terrorist" group by a local government; how would I react to a similar decision, involving any similar citizens' group, issued by the federal government? The Left is already talking about 'packing' the Supreme Court, at their first opportunity. If that actually happens, how will I view any decisions made by a 'packed' court?
In such circumstances, it may be important to dial in more than a gut-level 'right or wrong' feeling, or the fact that 'some @sshole' (like yours truly ;^) might have been arguing 'something similar' online.
But since we're all here on FreeRepublic, I'm probably preaching to the choir...