Hey, I'm not sure if anyone can answer this here, but I'm an EU citizen and I'm planning on visiting friends in Montreal. I want to travel via the US as I've never been there before but as I'll be flying home from Canada. Will this be an issue for immigration when I land in the US? I was planning on travelling by train up, but I haven't booked my tickets. Do I need to do this in advance? I mean in terms of immigration, not in terms of getting a seat. Thanks for your help! ;D