Also, there are more basements up north because back in the day, they needed to put coal in the furnaces and the furnaces back then were so large they would take up half the basement. The trucks would back up with the coal and let it flow down the chutes to people's basements...but this all happened more or less north of the Mason-Dixon line since we have a more temperate climate in TX, in addition to our high water tables. However, in some places of Texas you would have to have used dynamite to get through the rock it is so hard. When I grew up in Del Rio, TX, my dad had to take a pick-ax to the ground just so he could plant a tree! In the Dallas area, some of the older mansions such as in Highland Park have basements, but they are really high dollar.