Before the 1800s, much farm work, transportation, heating, and home chores were done with muscle power and wood burning. As coal, petroleum, natural gas, and later nuclear energy were applied to replace muscle power, our country experienced rapid growth in industrial production, food production, shipping, travel, and a growing economy. Also, comforts and conveniences at home and work, such as air conditioning, refrigeration, cooking, dishwashers, automatic washers, and more.