I think the Brooklynese accent has to do with roots in the Irish Channel neighborhood. At least that is what I have learned from James Lee Burke's novels.
This guy looks like he'll be talking with a Southron drawl any day now.
The truth is that there are MANY Southern accents. People who are not from this region tend to think that there is only the drawl, but that is not the case at all. I am from Mobile, and our accent is very different from the north Alabama accent, which tends to be a bit nasal.
My father was from New Orleans, and all of my cousins have the regional accent. My wife says that I pick it up when I am around them.
The same ethnic groups who settled in the Northeast in the 1800's also settled in the coastal cities of the South. (Conventional history tends to ignore the fact that there was 19th century European immigration to all parts of the US, although most people went through the Atlantic ports.)
The Brooklyn-on-the-Bayou accent comes from the fact that many Irish, Italians, and Germans came to New Orleans during the 1840's and 50's, adding to the French, Spanish, and Anglo populations already present.
Older Mobilians often have an accent similar to that of New Orleans, eg, foist, for first, choich, for church, etc.
New Orleans also has a vocabulary all its own. A "banquette" is a sidewalk, the "neutral ground" is the median. One "goes by" "ya mama n 'em's ', perhaps on the way to "make groceries." New Orleanian pronunciations of French words are also unique, eg, "Chottis" for Chartres St.
I am happy to report that all of my "dawlin" cousins got out of the area before the storm. All are alive and well, although they have lost so much.
One positive outcome of the New Orleans diaspora is that there's gonna be some mighty fine cookin' all over the USA!
Ever since I knew what a Brooklyn accent sounded like, I've always thought that's what the folks in NO sound like. Some folks on the MS Gulf Coast sound the same way.
If you think the Cajuns talk funny, wait until Ophellia hits South Carolina and the press inteviews some of the Gullah Geechee folk.
This Noo Yawker was mightily amazed many years ago to hear NO natives speak pure Brooklynese.
One theory is that the NooYawk accent was actually copied from the NO accent ... coastal marine commercial intercourse and all that.
Generations of East Coast nuns at the local Catholic schools.
Creole dialect