I strongly suggest that you check with the National Park Service for accurate tours. The horse-buggy tours are more for entertainment than historical facts.

The Jean Lafitte national Park has an office located just below one of the finest restaurants in town; Bella Luna, in the French Market.
There's also a Natl Park office on Decatur Street in the 500 block.
The Old US Mint has some tours. That's located at Decatur Street and Esplanade. There's lots of Jazz History artifacts there that you must see. I tell people to go there lots of times...

Also Louis Armstrong's personal trumpet is on-permanant-display at the Hard Rock Cafe (N. Peters Street). It's on the 2nd floor. So, if you go during the day, you will have to ask to see it up there.

Good luck and have an enjoyable visit.
-Gene