Pecan pie is an American creation.
Pecans are native to North America. The nuts were propagated by Native Americans as far north as Illinois and the southern part of Iowa, according to Edgar Rose, a former engineer and self-made pecan pie expert who lives in Illinois.
Pecans grew along areas watered by the Mississippi River, spreading a bit to the east into Alabama. Following the Civil War, commercial developers brought in a few varieties of pecans to grow in Georgia (the state is now the main commercial grower of pecans in the U.S.). Grafted pecan trees also became prevalent in Louisiana in the mid to late 1800s. The name of the nut itself is derived from the French word "pacane", which is taken from the Algonquian word for “nut.” That may help explain why some believe the French invented the pecan pie after settling in New Orleans, though there’s seemingly little evidence to support that.
The earliest printed pecan recipes began popping up in Texas cookbooks in 1870s and 1880s. The first recipe that most closely resembles what we know today as pecan pie was published in 1898 in a church charity cookbook in St. Louis, but it was sent in by a Texas woman.
By the beginning of the 20th century, recipes for pecan pie had started appearing outside of Texas, but the pie wouldn’t surge in popularity until the mid 1920s. That’s when the manufacturer of Karo syrup began printing a recipe for pecan pie on cans of the product, as James McWilliams noted in The Pecan: A History of America's Native Nut. Wide distribution of Karo syrup introduced many people to pecan pie, who found it was quite simple to make.
Technically classified as a “sugar pie,” the classic pecan pie recipe promulgated by the makers of Karo syrup uses a cup of the product in the mixture, along with eggs, sugar, butter, vanilla extract, and of course, pecans. Alternatives for Karo syrup include brown sugar and molasses, and some recipes add bourbon, rum, or whiskey into the mix. Pecan pie is nearly always baked in a traditional pie crust verses a crumble crust or a cookie crust.
As with any classic dish, near-countless variations have emerged. Popular additions to the traditional pecan pie include bourbon, whiskey, shredded coconut, and chocolate. There are also pecan pie-cheesecake hybrids, pecan hand pies, and, strangely enough, pseudo-healthy versions involving chia seeds. Molasses or brown sugar sometimes serve as a substitute for the corn syrup, an ingredient that’s gotten a bad rap from nutrition advocates in recent years.
The dense combination of butter, sugar, corn syrup, and eggs create the gooey interior of pecan pie, which complements the crispiness of the top layer. While baking, the pecans rise to the top, leaving a gooey layer of sugary custard below.
Early 20th century recipes for pecan pie occasionally contained items such as milk and raisins, but once the Karo syrup recipe spread across the country, the ingredients changed little (barring personal tweaks and individual preferences). The majority of pecan pie recipes published today are still based on the traditional Karo syrup recipe.
How did it become a Thanksgiving staple?
With the advent of corn syrup and a pecan surplus, the popularity of the pies spread across the country. Pecan harvesting begins in late September and extends into November, making the timing just right to fuel pecan pie baking for the holiday.
Font: Eater - A brief History of Pecan Pie.