On your fourth day in New Orleans, we recommend starting with a swamp tour and then exploring the Garden District. Especially if travel plans only allow a half day, you can spend as much or as little time as you want in this district.
Consider taking an airboat tour, a quick way to explore the bayou. We had a good experience with Airboat Adventures, and they included pickup transportation. Airboat tours are loud, and they provide ear protection for this reason. You’ll explore the canals and drift past alligators. The bigger boats have to stick to the main channels, while smaller boats can navigate wherever they like.
Once back in New Orleans, take the St. Charles streetcar and get off near Washington Avenue. This mode may be a little slower than others, but it’s the scenic route.
At the Washington Avenue, you can walk to Lafayette Cemetery No. 1. It was closed to the public when we were there, and we were only able to peek through the gates. A self-guided walk through is likely enough, but cemetery tours do exist.
After the cemetery, take a walk and admire the many historic homes around Washington Avenue, Coliseum Street, and Chestnut Street.

For the afternoon, make your way to Magazine Street. Enjoy some shopping, especially between Louisiana Avenue and Washington Avenue. We recommend Dat Dog for their creative hot dogs and Empanola for yummy and creative empanadas.

We found the shopping to be on the more upscale side, so if that is not for you, this is probably a neighborhood that you can fit into a few hours. We enjoyed looking at the artistic shops.
For dinner, we recommend Saffron Nola, with its modern take on Indian food. Everything we tried was full of mouth-watering flavor.

If you are a history buff, the National WWII Museum is world class. Its many exhibits could occupy hours.
New Orleans is a great place for a Jazz Brunch. We liked Cafe Sbisa and Palace Cafe. They are classic places to eat with rotating menus, and they are more reasonable that some other restaurants. Brunch is usually only offered on weekends, and reservations are recommended.