Proving yet again that it's much easier for a propagandist to make outrageous claims than it is to refute them in detail.
But I note the words you've quoted are essentially correct:
Sure, but not necessarily Deep Confederate Southern origin.
Sure, but "goes from" does not equate to "produced in", especially not to "produced in the Deep South".
Referring to raw cotton, a few million dollars of the total.
Your author does seem to recognize the difference between Deep South cotton and all other exports, but does not seem to realize that those other exports were not at all necessarily "Southern".
Irrelevant for reasons I provided in a previous posting. The trade was eventually going to Europe, regardless of where it was produced in the South.