Here some info for traveling by train from the Big A, Atlanta on the AmtrakCrescent line to New Orleans. 

Coach Price - $74 - reduce by 10% for your AAA or NARP (Nationa Association of RailRoad Passengers) = $66.60 one way from Atlanta.  I always upgrade to Sleeper accomidations which runs about $125 to $200 the best price comes from booking far in advance, you can save hundreds on a sleeper which accomidates two adults easy.  With sleeper accomidations the two passengers are allowed FREE MEALS IN THE DINNING CAR.  This is a huge advantage because Amtrak food is stellar, meaning excellent! 

Break it down this way - one way airfare is about $150 on Airtran or Delta on a good day so two adults = $300.00 plus about $50 on the airport shuttle to the Quarter so lets say $350.00

Amtrak two adults - kids under 6 are free and under 16 are 1/2 price -  two adults $148.00 add the sleeper $125 = $273.00 remember the free meals!  Cab fare to the Quarter from the Amtrak stations is about $10 so total damage is $283.00.

So you save $67 and have a really nice ride in a sleeper car, so you have slept, talked and had a really nice view of the Southern Landscape and an incredible view going over Lake Pontchitran. 

From Atlanta you leave at 8:05 AM so to the Dining Car for Breakfast you go, try the Quiche it's the bomb.  Go to the sleeper for a nap, wake up around 10AM fo the free neewspaper and a cup of JAVA which is free and provided in the sleeper section.  Lunch at 12:00, try the Pasta with chicken and white wine.  Back to the sleeper for a nap.  Wake up, have a beer or cocktail, head to dinner; get the Steak, it's incredible.  Viola, 7:30pm you arrive in the Big Easy, 10 minute cab ride to the Quarter.  If you stay in the Magizine Street Area you could just walk from the station. 

It's Greener, Cheaper and more fun and no pat down or a TSA agent feeling your private areas. - Check it out but try to book at least 2 to 3 months in advance.  Amtrak is getting popular and the better deals go away 4 to 6 weekes before departure.