First of all, the document was never published and is not authenticated -- could easily be some later construction. Indeed, it sounds like a later construction, compared to the other secession documents.
But even so, read it again, pal.
It contains not one word about some major "usurpation" or "abuse," "injury" or "oppression" which did happen, but only expressions of fear about what might happen in the future.
Southerners had no real reasons to secede, nor to seize Federal properties, nor to fire on Federal forces, nor to declare war on the United States.
But they did it anyway.
The South chose its fate, and should now be happy with it.
You sound pretty vindictive. What's your deal?
It contains not one word about some major "usurpation" or "abuse," "injury" or "oppression" which did happen, but only expressions of fear about what might happen in the future.
Conceding nothing on the question of whether something did happen (the Texans said the Congress DID refuse to appropriate money for defending the frontier in Texas), and setting that aside for a minute, who says they had to prove a past injury to anybody?
Either they were sovereign and could decide their own fate, or they were not. If they were sovereign, that means, no apologies and no explanations to anybody. Kings don't explain themselves -- that is what sovereign means.
You're setting yourself up to be their judge. They quite rightly demanded a test of arms over that proposition, just as we would if China's politburo thugs decided that we needed their permission to hold elections.
And let's take a quick look, as a practical proposition, at the question of whether the Southern States should have waited until they were being demonstrably abused..... but wait, by whose sayso?
If the Northern States were extracting vast sums of money from the Southern cotton trade, and the South complained, what would Lincoln and the Republican Congress do? Deny it. No damage. No injury. Zero complaint. Go home and go back to work -- slaves! (The North was really in favor of slavery. They just had a beef, that the Southerners were not slaving for them quite enough yet!)
So the South decides they've been injured and demonstrably so (remember, Lincoln is denying it and pettifogging it, and Northern orators are loudly pooh-poohing Southern complaints) ...... what should they do then? Secede then, after the fact, after Lincoln has covered the South with federalized troops from other States -- from Massachusetts and Pennsylvania and New York and Ohio? Yes, that would be the time to try the secession issue. But wait -- Lincoln says, NO, you can't secede! You must get the permission of the other States -- DENIED!!!
So, given the South is being sucked dry, drained of cash, gradually driven to bankruptcy by Northern tariff and business arrangements ..... what would you recommend they do for a remedy under those circumstances? "Lie back and enjoy it"?
Well?