Earlier quoted context omitted.
> I am reminded by the perhaps revisionist history but still applicable belief that slavery was really ended by industrialization making abolition economically advantageous and not actually a socially driven movement. (In reality it was certainly a convoluted mixture of the two I'm sure.) More or less. Adam Smith famously wrote that slavery was economically detrimental way back in 1776. It still took nearly 100 years…
Mississippi declaration of secession. "“Our position is thoroughly identified with the institution of slavery — the greatest material interest of the world....Its labor supplies the product which constitutes by far the largest and most important portions of commerce of the earth.” Georgia "“The prohibition of slavery in the Territories… is destructive of our rights and interests.”
> Our position is thoroughly identified with the institution of slavery-- the greatest material interest of the world. Its labor supplies the product which constitutes by far the largest and most important portions of commerce of the earth. These products are peculiar to the climate verging on the tropical regions, and by an imperious law of nature, none but the black race can bear exposure to the tropical sun. These products have become necessities of the world, and a blow at slavery is a blow at commerce and civilization. That blow has been long aimed at the institution, and was at the point of reaching its consummation. There was no choice left us but submission to the mandates of abolition, or a dissolution of the Union, whose principles had been subverted to work out our ruin
Also, they clearly make the case that cotton was the most important good in the world, perhaps imploring the intercession of foreign powers.
I think it's worth pointing out though that these people were not being honest with themselves - nothing in their argument about the importance of cotton suggests it couldn't have been done with wage labor. They are dancing around the fact that only a very few benefit from slavery.