The hickory nut got its name from the Algonquin Indians. The Indians called the nut "powcohicora" but white settlers shortened the name to "hickory". The nut is part of the walnut family and related to the pecan.
The settlers would grind the nuts, add water and produce a milky liquid which was used in soups, cornmeal cakes and hominy. They also made a beverage called "pohickory". The nuts were a useful food because they had a variety of uses and would store for up to a year.
Today hickory nuts are used in pies, nut breads and cakes. They are not widely used because they tend to have very hard outer shells with take a lot of work to crack and the yield is very low.
There are three types of hickory with edible nuts.
From the American Heritage Cookbook 1964
Sift together the flour, baking soda, cinnamon and nutmeg, and set aside. Cream butter until soft, then cream in the sugar, a little at a time until the mixture is smooth. Beat egg yolks hard and add to the mixture, then add lemon juice. Mix raisins and nuts with the flour combination and add to batter alternating with whiskey. Beat egg whites and salt together until they stand in peaks, then fold into batter gently but thoroughly. Pour into 2 well-greased loaf pans and bake in a preheated 205F oven for 2 - 2 1/2 hours or until cake pulls away from the sides of the pan.