Simple, basic questions
 

Very infrequent Amtrak traveler here. I have a trip coming up soon out of Chicago. What is cutoff time for boarding? I have the app and my trip shows on it with a QR code. Do I need anything else to board?

Amtrak's website says the gates at Chicago Union Station close 5 minutes before train departure. I wouldn't cut it nearly that close, since, depending on which train you are taking, you might not have a reserved seat, so you would want to be at the front of the line to get a better seat. The QR code is all you need for a ticket--one of the conductors will scan your code. I usually print the ticket from my e mail just in case my phone dies, but I'm kind of old school.

Note that they can by policy ask for government photo ID to board or on the train, but I have never been asked in years & years of regular Amtrak travel.

Will you be checking any bags?

No bags. Sounds so easy. Thanks for the replies.

The conductor's scanning device will randomly prompt to check an ID when they scan the tickets. It is random and fairly infrequent, but it DOES happen.

If they get the prompt and you don't have ID, you are getting off at the next stop. Yes, it is pretty rare, but the consequences of not having an ID if they get the prompt are pretty severe, so just carry ID.

I was asked for ID a few weeks ago - I think the conductor said it was a TSA random check and he was prompted by his scanning device- fortunately I had my Passport with me.
Another two passengers were also asked to provide ID as well.