[eyelidlessness]

I don't think this is entirely accurate.

It's absolutely the case that the South was motivated to secede by the issue of slavery. It is not the case that the North was, they were motivated by the preservation of the Union. Lincoln said as much. Abolition was used by the Union as a weapon, not as a cause unto itself.

It's seen as revisionist to question the moral character of the US Civil War, but you have a President who said explicitly that he would preserve slavery if it would preserve the Union, and abolition that exempted Northern states.

Slavery was (partially[1]) abolished in the US not because there was some high-minded federal government that thought it was the right thing to do, but because abolitionists worked hard for generations to compel it. The fact that a war was fought over it only speaks to the fact that slavery was so entrenched in the Southern states that it considered the progression toward abolition an existential threat.

[1] Slavery was never fully abolished in the US, and we should be careful not to forget that. It's no mistake that the amendment to restrict slavery to punishment for crime also coincided with the beginning of a trend of criminalizing activities and lifestyles of former slaves and their descendants.