Complex sentence: Many families kept dozens of hogs as their insurance against crop failures, largely because one could raise hogs almost for free in the forested, nut-tree dominated uplands (covered with the typical Appalachian chestnut-oak-hickory forest).
Split into simpler sentences: Many families kept dozens of hogs as their insurance against crop failures. One could raise hogs almost for free in the forested, nut-tree dominated uplands (covered with the typical Appalachian chestnut-oak-hickory forest).