The Auto Train is run by Amtrak. It starts in Lorton Virginia (just off the DC beltway) and ends at Sanford Florida (about 45 min north of WDW)
There's no stops, it's direct. You get on the "people" cars, and they put your vehicle in one of the "car" cars.... so it goes with you!!
The train leaves VA at 4pm and arrives at Sanford at 8am the next morning. They feed you on the train, and there's a lounge car where they show movies. It's fun.. a nice way to travel if you don't want to fly... driving 22+ hrs to florida makes me cringe
We always travel coach..they have sleeper cars..but they're too expensive for me

The coach seats are very roomy, recline quite a bit, and have a "recliner" type leg rest. I've never had any trouble sleeping in them!!
The AutoTrain is pretty popular for travelers and especially snowbirds in PA, MD, VA etc. The price is good too.... much cheaper than flying and renting a car. Once all 5 of us + our minivan... cost less than $1K round trip!! Smaller cars are cheaper.
2 BIG bonuses to the Autotrain.... you can take ANYTHING with you...as long as it fits in your car!! No packing problems..or souvie shopping restraints either!! The other thing is Amtrak has an AWESOME cancellation policy! You can get a full refund minus 10% up to 2 hours before your train is to leave if you have to cancel!!! I like that
Paula