That same contempt was evident in the writings from the 1860s. New York, Boston, Chicago, etc. hated and despised the Southern people, considering them uneducated, backwards and immoral.
Same as today, but "Flyover country" is a lot bigger nowadays. The large coastal cities are still dripping with contempt for people who are not like them.
And that is precisely the point on which you are wrong.
In fact, New Yorkers especially the very financial & commercial interests which so, so vex your mind, those New Yorkers were the close political, economic and even social allies of Southern cotton producers.
They were happy to support secession, even wished to secede themselves, and they just as ardently proposed whatever political accommodations Southerners might accept.
In early 1861 there was no daylight between those New York Democrats and their Southern Democrat allies.
Until, until... until, that is, those Southern buddy-buddies of the New York commercial interests repudiated their debts to Northerners.
Now, now suddenly, New Yorkers of all political, economic and social conditions began to realize they had been had.
And New Yorkers -- Democrat, Republican, Know-nothings, whatever -- New Yorkers don't like being screwed over, period.
So suddenly, "Ape" Lincoln and his "Black Republicans" did not look so, so cartoonish and evil.
Suddenly, even New Yorkers who loved the South realized something must be done, and briefly switched sides to support Republicans.
But by 1868 New Yorkers reverted to true form and again voted with Southern Democrats against the Union war hero, US Grant.