So, I decided to put together a map based off a book: New Orleans: America's Most Fortified City. It details the extraordinary lengths various countries have gone to to protect New Orleans from its enemies. New Orleans is a strategically VITAL location. If you were to go up to some of the people who toiled and gave their blood, sweat, and tears to defending the city and told them, "Guess what, some people in America want to abandon New Orleans," well, let's just say he wouldn't take it too kindly.
More on the Forts of Louisiana.
The Google Earth Post and the Google Earth Map (API).
A closer look:
The other thing I learned doing this is all the coastal erosion that's happened over the past 300 years or so. There are some areas that don't exist anymore.
Look at Tower Dupre (which was originally built on dry land):
Small image I used to mark forts. You might have to download it and load it into Google Earth.
I'd love to get together a tour of these locations to see how some of them survived Katrina.