We American chestnut trees lived in the eastern United States because its climate and soil were kind to us. We don't like limey soils - soils high in calcium, like those soils in the western United States.
First explorers reported that "Where there be mountains, there be chestnuts."
Early European settlers cut down many trees to build their log cabins and to heat them during the cold winter months. That logging activity probably increased the population of my ancestors.
Since we produce more nuts and sprout faster than most trees, we repopulated the cleared areas faster than other trees. We were the dominant tree of the Appalachians.