Both Amtrak and Greyhound do that route. Both websites are awkward to use, , so you can call them. Amtrak 1-800-872-7245Greyhound 1-800-231-2222 You may find they are not that much cheaper.
The first poster is correct. However, cheaper doesn t always mean better. Greyhound has weird schedule, lots of stops and they draw a pretty whacked out crowd for passengers. If you take the bus, be careful who you make friends with on the ride.
Train AmtrakBus Greyhound