If Im coming from birmingham airport to ATL and connecting to a flight to Montreal, will I have to go through customs and security? Also will my checked bags be automatically transfered to the connecting flight or do I have to claim luggage ar ATL and take them to the terminal for the flight for montreal? And about how long will the transferring take. Ive only got 54 minutes from my arrival time to the departure time of next flight. (sorry first time flyer and not familiar with proper traveling etiquette) thanks for any help that can be given.