I just returned from St. Louis to Central Florida last summer. I took I-55 south to Memphis,( I-269 is a loop around Memphis that is an easy drive to I-22) picked up I-22 to Tupelo, MS then turned south on US 45 to Meridian, MS then east on US 80 to Montgomery, AL then south on US 231 to I-10. I avoided Birmingham, AL as there is all kinds of road construction around that area and it is slow going with traffic delays plus rough road.This is a good choice with less traffic. Atlanta is a nightmare to get through due to traffic and construction. I live out side of Orlando so if I can be of additional help let me know.Safe travels and enjoy the trip!