Final answer:
Food at Mount Vernon was preserved using drying and smoking methods, salt, and root cellars, as refrigeration and canning were not yet invented during that time.
Step-by-step explanation:
At Mount Vernon, food was preserved primarily through traditional methods that were available before the invention of modern canning and refrigeration techniques.
These methods included drying and smoking, using salt, and storing food in root cellars to keep it cool and extend its shelf life.
Smoking meat, particularly in a pit BBQ style, was favored in the US South because it made the meat easier to eat, improved its flavor, and prevented spoilage for a longer period which was crucial due to the lack of protein in poor people's diets at that time.
Moreover, salt played a significant role in food preservation by reducing water activity, which helped prevent the growth of spoilage-causing microorganisms. Root cellars provided a cool environment for storing fruits and vegetables, extending their usability far beyond their natural harvest season.