The Southern States would have interposed no objection to the secession of any Northern State; the Northern States are thrown into a perfect paroxysm of rage at the mere whisper of Southern secession. Why? They know the South is the main prop and support of the Federal system.
Original passage & context
"There is this difference between the Northern and Southern States, which illustrates the exact nature of the quarrel between the two sections: That, while the Southern States, in the Union, would have interposed no objection to the secession of any Northern State, the Northern States, on the other hand, are thrown into a perfect paroxysm of rage at the mere whisper of an intention to secede, on the part of any State of the South. [...] They know that the South is the main prop and support of the Federal system. They know that it is Southern productions that constitute the surplus wealth of the nation, and enables us to import so largely from foreign countries."
New Orleans's fire-eater daily makes the Deep-South PRESS case for the cascade on economic rather than constitutional grounds: the North rages at Southern secession because it needs the section it professes to despise — the South is "the main prop and support of the Federal system." The mirror image of Greeley's "letting them go in peace" (ch1 se-002): the Crescent claims the South would gladly let the North secede. Two paragraphs joined with [...]. The "barbaric" line it rebuts midway is Sumner's, from the Senate (the caning event). This is the one in-window Deep-South newspaper editorial available for the cascade — the Southern side of these weeks is otherwise carried here by convention and declaration voices. Fetched from the AHA "Sixteen Months to Sumter" archive.