The "hay box" slow cooking method was often used on the wagon trains that moved west during the mid-1800's. The cooking would be started using the morning fire, the cooking pot with the heated food would be placed in the insulated box, and set in the covered wagon. Once reaching the evening camp, the meal now cooked could be quickly heated and served. Applewood Books has a reprint of "The Fireless Cook Book" , M. J. Mitchell, 1913.
Another interesting book from Applewood, is a reprint of "The Prairie Traveler- A Handbook for Overland Exxpeditions ", R. B. Marcy, Capt U.S. Army, 1859