creamy vegetable pie recipes date back to medieval europe. it was a favorite of henry viii of england. he was known to eat a great number of sweet potato pies at a time believing they were an aphrodisiac. sweet potato pie appears in the southern united states from the early colonial days. like many sweet potato recipes, sweet potato pie was likely developed by the black slaves from traditional african cuisine. it is a staple of soul food today. recipes for sweet potato pie first appeared in printed cookbooks in the 18th century. it was included with savory vegetable dishes. by the 19th century, sweet potato pie was considered a dessert.