I have always lived in the midwest or northeast, where pumpkin pie was always served. I have made sweet potato pie more for curiosity, but the convenience of canned pumpkin made pumpkin pie my preference.
My sister is a PhD candidate in Mississippi. She was commenting this evening she could only find sweet potato pie, but no pumpkin. After some personal effort, she has locate some canned pumpkin.
We began to speculate if pumpkin was more successfully grown in the north and sweet potato in the south; which may account for regional preference. Of course, despite alleged homogenization of American tastes, clearly there are regional preferences for either pumpkin or sweet potato pie.
Is sweet potato or pumpkin pie preference related to the Mason-Dixon line or agricultural-climate zones or? Whatever insight you may have is appreciated.