I’ll start with luggage, be careful how you pack for the roomette. You won’t have much space in there. The rolling suitcase that I normally travel with is 14 inches wide, stands 23 inches tall, and is 7 inches thick. If I had two of those bags, I could just barely fit both of them side by side in the cubbyhole above the hall. The same sized bag can also fit underneath your seats. One bag could be a little wider than mine by maybe an inch or two, the other I’d say could be approximately 5 or 6 inches wider. They could not be much taller or thicker and still fit underneath the seats. There is also room for a shoulder bag next to the larger of the two seats.
If you need more or larger bags than that, you had best check some luggage.
Next, your sleeper tickets qualify you as a First Class passenger on Amtrak. As a first class passenger you are entitled to utilize Amtrak's first class lounges in DC and Chicago. These lounges are a nice quiet refuge in the often-bustling train station. They have nice plush chairs, conference rooms, computer terminals, newspapers, TV's, free soft drinks, juices, coffee, tea and clean safe bathrooms. They also allow you to board your train before the rest of the masses.
In DC the Club Acela Lounge is located behind the information kiosk, which is in the center of the waiting areas between gates D & E. There are two large wooden doors there, ring the bell to the right of the door and the attendant will let you in. Show your tickets and you’re in. They will escort you to your train when it’s time.
In Chicago the lounge is called the "Metropolitan Lounge". It is located on the lower level of Union Station, which is also the track level. If you are standing in front of the Amtrak ticket windows, then the Amtrak waiting area is to your left. When you enter the main Amtrak waiting area through a sliding glass door, just walk forward and slightly to the left. There should be another sliding glass door along with a sign, unless they've changed the entrance in the last few months. Again, just show your tickets and relax. Note the Chicago lounge can be very busy and it sometimes can be hard to get a seat, but you still get the free stuff and priority boarding.
In Chicago they will also give you a card. On that card is the time you must return to the lounge in order to catch your train. If you do leave the lounge to eat or tour the city, just flash the card to the attendant when you return to the lounge.
If you haven’t already, I would highly suggest checking out On Track On Lines’
Hints and Tips.
Finally, have a great trip!