I have heard it said by an authoritative primary source whose name I am not at liberty to mention that Jazz can't even be said to have begun specifically in New Orleans, but that it emerged simultaneously right across the USA in numerous little pockets.

New Orleans spawned Armstrong and Bechet and they were the biggest influences on the creation of Jazz as we know it. In fact, Louis was invited to New York from Chicago by Fletcher Henderson to teach Jazzers there how to swing.

Thats why New Orleans gets the credit.

I'll have to return to this next week though as I am needed elsewhere right now.

I look forward to saeeing how this thread had developed.