One reason I love the train

Here's the policy on changing or canceling your Amtrak reservation:

If you change your reservation, reprint your eTicket yourself or obtain a new eTicket at Quik-Trak or from a station ticket agent (if either are available). If your travel plans change, call us before departure to modify your reservation. If you have not done this and do not board your train, your entire reservation will be canceled; the money paid for the trip will be stored in an eVoucher that you may redeem at an Amtrak station ticket office for future travel.

So you don't pay to change your train from one day or time to another. You only pay if you go to a more expensive trip (like from a regional to the Acela), and if you go to less expensive one, they refund you the difference (cheerfully, I may add - I have done this and gotten money back from them!). If you cancel before the trip, they refund it all. And if you just don't show up, they give you a voucher for the full fare to be used on another train.

Unlike the airlines and their "change fee" (which might be more than the ticket cost, depending).