 After the development of larger and faster-growing hogs (due to crosses between European and Asian breeds) in the 18th and 19th century in the United States, backyard and small-scale hog production provided an inexpensive means of converting waste food, crop waste, and garbage into calories (in a relatively small space and in a relatively short period of time). Many of those calories came in the form of fat and rendered lard. Lard was used for almost all cooking and was a fundamental component in many common homestead foods (many that today are still regarded as holiday and comfort foods) like biscuits and pies. The economic / caloric necessity of consuming lard and other saved fats may have led to the popularity of fried foods, not only in the US, but worldwide. In the 19th century cast iron became widely available for use in cooking. The combination of flour, lard, a chicken and a heavy pan placed over a relatively controllable flame became the beginning of today's fried chicken.
