raysen

I am planning on buying two national 30 day unlimited rail passes. I just have a couple of questions before I do.
We are from UK and will be in America from sept 6th but wont be requiring to use the pass until after a couple of weeks.
We don't know the exact date when our first trip will be so is it posible to buy the pass when we are over there just before we wish to use it? or will we have to buy it online before we go?

I tried emailing amtrak but some error came up and couldn't process the questions so I thought I'd ask you lovely lot!!
Cheers guys

xx

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