Sort History of New Orleans
The French settled this port city and at that time the low lying areas which were flooding were wetlands. Much of the city which was north, including the French Quarter and the Garden District did not flood or only flooded very little.
Since the United States made the "Louisiana Purchase" from the French, New Orleans has grown over the years into a bustling port city, much due to the reasons the French settled there in the first place, it lies at the mouth of the Mississippi river. What has happened is river traffic on the Mississippi has become so important that the Army Core had spent millions trying to keep the Mississipi from doing what it has done several times, change course. Various dams,levees and other methods including dredging to keep the current swift and keep the silt from building up means the silt which created the wetlands which once acted as a buffer between lower NO and the water have gone. The water/nature was just doing what it normally does before man tried to stop it.
There is some talk now about expanding a small project which has been slowly allowing the Mississipi to have controled floods in selected areas to help restore former wet lands. The project costs millions per year and would cost millions more to do on any large scale. It would take decades before any major return/filling in of the wet lands would occur however. In the end though, allowing some of that land to be reclamied by nature would be probably an easier solution than building higher and maintaining higher levees and any of the other elaborate flood control measures spoken of recently.
Much of the southern NO area is/was basically swamp land. Which back in the days before bug control was infested with MOs during the summer, which brought plagues of yellow fever each year. When Irish immigrants began arriving by ship loads during the flight from the potato famine, many didn't last a month before contracting and dying of yellow fever. If you look at old maps of NO, with "fever lies" drawn, the wealthy abandoned their town houses in parts of NO soon as summer hit or the first cases of yellow fever were reported. They high-tailed it up to dryer areas up north (which were above the fever lines), and those trying to cross could be shot.
One of the reasons the wet lands were filled in was because of MO control. When modern medical science discovered it wasn't because of "bad airs" or "voodoo" that spread yellow fever, but the MOs, the answer was simple; get rid of MO breeding brounds (areas of stagnat water - swamps/bogs).
To get a good idea of "old" NO, there is alwasy Bette Davis in "Jezebel", which is worth seeing IMHO for George Brent (Buck Cantrell), who speaks with such a smooth drawl you could spread it on biscuts!
Sorry for the long post.
Launderess