[DiogenesLamp]

Your own principle defeats your wretched argument.

It is the principle of the Declaration of Independence, and yes, it eventually defeated slavery, but when it was initially written it was intended to ignore the condition known as slavery.

Slaves were suffering abuse.

Slaves thought your Confederacy was intolerable.

I'm sure they didn't think much of the slave owning US Confederacy either.

Slaves had no say in the Union at that time. It wasn't until they served the purpose of propaganda that they ever got a say in anything.

Pointing out the condition of slavery as an argument against independence merely argues against the Colonists right to have independence because they too were slaverholders at the time.

The point here is that you cannot impugn the legitimacy of Southern states gaining Independence without damaging the legitimacy of the original thirteen colonies gaining independence. Whatever applies to the Southern states, must also apply to the original colonies four score and seven years" earlier.

If slavery delegitimizes the Southern state's right to independence, then it must also delegitimize the original Colonies right to independence.

They too were a slave owning Confederacy seceding from a Union and led by a slave owning General from Virginia.

[x]

If slavery delegitimizes the Southern state's right to independence, then it must also delegitimize the original Colonies right to independence.

Not necessarily. Slavery was a centerpiece -- the cornerstone -- of the CSA, but not of the American revolutionaries of 1776.

Everyone knew the attitude of the CSA government towards slavery. Things were more ambiguous in the 1770s.

African-Americans were fighting in the patriot Army. Pennsylvania committed itself to the abolition of slavery in 1780, Massachusetts in 1783 (based on the 1780 state constitution).

It wasn't clear to everyone in the Revolutionary era that independence would mean the continuation of slavery. It was in the Confederate states in the 1860s.

[BroJoeK]

DiogenesLamp: "The point here is that you cannot impugn the legitimacy of Southern states gaining Independence without damaging the legitimacy of the original thirteen colonies gaining independence.
Whatever applies to the Southern states, must also apply to the original colonies four score and seven years" earlier."

Total nonsense.
First of all, even Thomas Jefferson understood that slavery was morally wrong, and blamed it on the Brits.
And most Founders believed that slavery must eventually be abolished.

By stark contrast, 1861 secessionists' Reasons for Secession documents spelled out in no uncertain terms that protecting slavery was their primary objective in declaring disunion.

Second, and more important, where 1776 Founders declared Independence of necessity, 1861 Fire Eaters declared their secession strictly "at pleasure", making their entire enterprise illegitimate from the beginning.