Meaning that you can even pick them up online, or in europe. When you purchase them, you tell them the dates you want to start travel (if you look online, you can see all the peak/off peak periods, I think your trip fits within the 'off-peak' time, saving tons of money. The prices online may be better than an agent, too!) and they're good for 30 days after that. So you can purchase them well in advance, no problem. If you don't travel on the dates you thought you would, just make sure to tell the agent and they said they'll adjust your pass so that it starts counting down from the first day you actually board a train.
There's a toll-free number to call, once you're in the states, posted on their website... make sure you note it down, cause that's who you call to make reservations (and probably to adjust the pass dates)
Labor Day weekend is the last big holiday for the summer - 2-4 September, this year (which is why it's still during the "peak" price period)
You will need to make reservations for every train (just like flying) though, I'm sure the passes will work if there's open seats on a train and you just show up. Because of transportation safety regs, though, I'm not sure if that will work, anymore...
<<calling Amtrak again>>
o0...they have the politest computer/on-hold system ever...0o
Ok, I found out that, indeed, you could theoretically 'hop a train' if there are seats available, and reservations can be accepted the same day as travel occurs. The downside is that this summer, particularly, the seats have been selling out, so you should make your reservations a couple days in advance at least.
I also confirmed that, no matter when you buy your passes, the countdown doesn't occur until you first board the train. If you order online, you can probably specify the 'off-peak' dates, so that you don't pay the higher price, and you can actually buy the passes whenever you wish, so it's all pretty flexible, however you wish to do it.
They seem pretty flexible, so I'm certain that any problems you might have can be resolved by a quick call to their toll-free number (in the states, that's numbers starting with (1-) 800, 866, 877, and 888)
As far as making the phone call? It's a Sunday, and I had nothing better to do, other than play Kickball today, so no problemo!