New Orleans as the New York of the South

[DINGO Joe]

It did have it's own exchange--the cotton exchange.  Turns out it wasn't enough.  Obviously, the Civil War turned the South into an economic backwater.  New Orleans has some geographic issues that would have guaranteed that it could never grow to NYC standards in the best case scenario anyway.

New Orleans actually has considerable limitations as a seaport in modern times too.  The Mississippi River is really the only North American river (well, the Colorado too) that rebuilt it's delta post ice age.  The Hudson, the Brazos, etc all have deltas submerge well below sea level.  The end result is that you have to navigate up river quite a distance to get to port.  As ships got bigger, navigation and maintaining channel depth became quite an issue too.  Houston is a much easier port to get in and out of logistically.  The railroad also made rivers less important.

[DINGO Joe]

could lack of AC kept the money away....New Oreans is brutal in the summer.  Sure, DC is a humid swamp and it certainly gets hot in NYC....but not hot like NO.

Yeah, I don't know how people wore wool and survived in this kind of climate pre-AC.