The Ordinances were just stating secession. The Declarations got more into the why, and the why was slavery, as they indeed declared. The big players put out the Declarations.
Far more instructive are the Ordinances of Secession, submitted individually by each of the seceding states. Their reason for secession was the same in each case. To retain and maintain their sovereignty.
Just stating secession, not so much into the why.
They claimed the northern states and the federal government had broken it's compact and violated the constitution, consequently they were no longer bound to the Union. They were unanimous on this assertion. Was slavery an issue? An underlying one most certainly, so far as it pertained to the over-riding necessity to protect state sovereignty from the unconstitutional actions, unlawful hostility, and outright aggression of the north.
Funny how it was always slavery that made these states suddenly push for state's rights. They didn't seem to mind losing state's rights under FDR, FDR never lost a southern state.
The Ordinances were all that mattered. They were the legal documents stating intent and action.
Any honest reading of them clearly reveals that the cause of maintaining and defending individual state sovereignty was the reason for them. The wording is clear, it’s meaning beyond doubt.
The interesting thing about the Ordinances is the fact that slavery is not even mentioned in most of them, and only fleetingly in the rest.
That’s because to the seceding states, slavery was a constitutionally protected institution, not an issue at all if only the Federal Union would honor it’s compact to the states and it’s sacred oath to the constitution.
But the Federal Union preferred to meddle in the affairs of the sovereign states, force it’s will upon them, and violate the very constitution it was sworn to uphold and defend.
Sound familiar? It should, since the liberty-smothering machinations of the central government oppress the states to this day.