We traveled with our 8 month old daughter from Long Island NY to Orlando (just over 1000 miles) by car, and she was a doll. Of course, it helped that she had her 5 and 4 year old brothers in the back seat to amuse her!

If your child is normally very content in the car seat, I would say that it should be no problem. I know some kids are car seat squirmers. I never had any of those. If you do, 3-4 days in the car might really be testing it. Be sure to bring extra of everything accessible to you.....diapers, drinks, snacks, toys, wipes, you name it. Your child may be too young for audio tapes or movies, but they are a great option for traveling with older kids so you may want to think about it for yours.

Someone introduced me to rice cakes when my daughter was about your childs age. They were a great self contained and somewhat healthy (I think!) snack that really saw us through a lot of trips when she was younger. They come in many flavors and travel well. My daughter still eats them as an on-the-go snack to this day, and she's 11. She loves the white cheddar.

I would really be hesitant about traveling by train. You are a captive audience in cramped quarters, and if your child has one of those "moments", you just have nowhere to go to get relief. Additionally, Amtraks fares are usually not significantly less than what it would cost you to fly.

Which brings me to the real reason I responded to your post. I know you said air travel is not an option. If you say that due to budgetary restraints, you may want to reconsider. Many markets have extremely low fares these days, fares that you might not even be aware of. You might be able to hold your child on the flight and thus you'd only be buying two plane tickets. The idea of spending 3 hours in a plane or 3-4 days in a car might be well worth a few dollars (or even less) that you might be saving by driving or taking a train. Also, it's 3 less nights each way that you have to pay for a hotel in a place you really didn't want to visit to begin with. Better to use those extra hotel nights at your destination.

Whichever way you go, have a great trip!