I have a cookbook from Winnfield, Louisiana "The Dixie Cookbook".  It was published before 1929; I am still trying to pin a date to it.  The pecan pie recipe has the following ingredients: sugar,  red karo,mashed pecans, eggs, butter size of walnut, and pinch of salt.  This is the recipe my grandmother used for years.  And it was delicious! I might have to make a pecan pie for Thanksgiving.