Once the dominant canopy hardwood of the eastern United States forest — an estimated four billion trees, prized for fast growth, rot-resistant timber, and an enormous annual crop of sweet edible nuts that fed people, livestock, and wildlife alike. In the early 1900s an introduced Asian fungus, chestnut blight (Cryphonectria parasitica), swept through and functionally destroyed it: by the 1950s the species was effectively extinct as a mature forest tree. Surviving root systems still send up sprouts from old stumps, but the blight almost always girdles and kills them before they can grow large enough to flower and reproduce. The honest reality for a gardener is that you cannot reliably grow a mature wild-type American chestnut today. The realistic paths are blight-resistant backcross hybrids from The American Chestnut Foundation or transgenic blight-tolerant lines still being deployed — not a pure wild seedling, which the blight will almost certainly kill.