First of all, do not confuse members of this genus which are the "true" chestnuts with another species called the horse chestnut which belongs to the species, (Aesculus hippocastanum).

At one time, large parts of the Northeast United States were covered with chestnut trees. Just after 1900, a fungal disease called chestnut blight swept through the native populations of the American Chestnut (Castanea dentata) killing millions of trees. Rare individuals may still be found in woodlots. Today, research is still ongoing to find American chestnut trees that are resistant to this disease.

Some of the other species of chestnut also produce edible nuts (BTW - horse chestnuts are considered poisonous unless given the proper treatment) but the American chestnut is still highly prized. Several of the other chestnut species are resistant to chestnut blight.