One primary advantage of rail travel is that you don't have to do the driving. This makes rail travel less tiring than car travel. You also don't have to deal with bad weather, road construction and potential car breakdowns.
While you're not driving, you have time to do other activities. You can sleep, read and socialize. Rail travel opens up opportunities to talk with people from other places. Additionally, you can drink alcohol on most U.S. trains, which is illegal while traveling by car.
It's easy to travel into large cities, such as Chicago, by rail. You won't have to deal with traffic jams or try to find a place to park.
If you don't need to be somewhere in a New York minute, rail travel beats air travel for long distances, too--especially if you don't like to fly. There are few waits for boarding at train stations, and you won't have to deal with turbulence or jet lag.
One of the biggest advantages to rail travel is the chance to sit back and view great scenery. Trains go off the beaten path, passing through beautiful areas such as the Rocky Mountains, New York's Hudson Valley, and the Blue Ridge Mountains.