Tuscalosa to DC is 800 miles, which is far more than we recommend you do in one day, its also about 200 miles more than professional drivers would be allowed to do. Even if you've "done it before" it really becomes a game of russian roulette where its only a matter of when you'll have a problem, not a matter of if.

The bigger issue is that while you might be able to complete that trip in one day, you've still got another major drive ahead of you the next day, so you'd be dealing with exhaustion while trying to navigate one of the busiest traffic corridors on the planet. In other words, you'll be endangering both yourself and the lives of the thousands of other people you'll be sharing the roads with. Its a bad idea, and I can't urge you strongly enough to not try it.