Amtrak does not come through Birmingham, Alabama, very much in a single day. The southbound Crescent stops in Birmingham, takes on passengers, and continues southward. Later in the day, the northbound Crescent stops in Birmingham, takes on passengers, and continues northward. Both versions of the Crescent are the only Amtrak trains that pass through Birmingham. Would it be accurate to assume that there was a lot more rail passenger activity in Birmingham before A-day? (Perhaps I should research that question locally.)
I'm not sure this is the best forum in which to have your question answered. I will leave it up for a few days in case anyone who visits this board knows and can help you out. However, I would recommend that give the Amtrak forum a try; I know there are several members who post there that know a lot about pre-Amtrak operations.
-Kyle