States that are below and defined by the old school Mason Dixon Line. Which is still in effect look at the college allstar game. The teams are separated by North and South. Dirty South is not also called the 3rd Coast which is the Gulf Coast. 3rd Coast States are Texas, Louisiana, Missippi, Alabama, and Florida the west part of that state because the east part of Florida is on the Atlantic.
It's called the dirty south because of all the crooked stuff that goes on. Like Bubba Sparx said the south is dirty now it's getting ugly.