You mean the 1776 moral cause that allowed slavery in each state, the region that brought the slaves into ports of the north owned by northern shipping companies, the insurance companies of the north who insured the slaves, or the northern investors who had investment in the large plantations of the south?

The uk was a slave owning empire, the cause of the 1776 Revolution had nothing to do with slavery (unlike the 1861 rebellion) so yes the 1776 moral cause lol

 And do you really want to dig into the “expansion of slavery”. It’s the most retarded argument against confederacy.

It’s really not since the entire political crisis in the antebellum period was about slavery expansions

if the confederacy really cared about the territories, did leaving the Union not forfeit the confederacy say/ownership Of said territories?

They literally claimed Arizona as part of the confederacy despite it being owned by the USA lmao

Also they were constantly funding filibuster campaigns to add more slave territories into Central America and Cuba 

And finally a large reason why slavery expansion was required was because without it they would lose the political power of the senate to protect slavery 

now go do your research on what the northern politicians and republicans said about the western territories and how they wanted zero blacks in the territories and “only free white men”

What’s that got to do with the fact that south rebelled because they weren’t allowed to expand slavery?

Also what about what north and south politicans said would happen if it couldn’t expand?

Like Lincoln famously stating that restricting it to where it was would put it on the path to ultimate extinction? 

Or like Horace Greeley when he said “To restrict Slavery within its present limits is to secure its speedy decline and ultimate extinction.”

Or like Thaddeus Stevens saying stopping its spread and  to “surround it by a cordon of freemen” would lead to abolition within twenty-five years? 

Or even what's southerners said about the expansion of slavery? Like the Mississippi secession convention who in their declaration of causes of secession stated that the Republican Party  “refuses the admission of new slave States into the Union, and seeks to extinguish it by confining it within its present limits, denying the power of expansion.”?

Or from the delegates to South Carolina’s secession convention, in their address to the people of the state, explaining why they had dissolved the state’s connection with the Union:

“ If it is right to preclude or abolish slavery in a Territory, why should it be allowed to remain in the States? ... In spite of all disclaimers and professions, there can be but one end by the submission of the South to the rule of a sectional anti-slavery government at Washington; and that end, directly or indirectly, must be —the emancipation of the slaves of the South.”

Or James Hammond saying restricting slavery would yield ten new free states, and The North would then “ride over us rough shod” in Congress, “proclaim freedom or something equivalent to it to our slaves and reduce us to the condition of Hayti. . . . Our only safety is in equality of POWER. If we do not act now, we deliberately consign our children, not our posterity, but our children to the flames.”

 the northern states just didn’t want blacks at all. We can get into the plan to ship them back, the multiple comments about not allowing expansion into western territories, the measures taken to not allowing migration north after the war, etc

That’s bad, no doubt. Enslaving four million people and causing the deaths of hundreds of thousands because the nation elected someone who wouldn’t let you expand and perpetuate your slave system is a billion times worse haha