Tamales have been around since approximately 500 B.C, with origins tracing back to the Mesoamerican cultures in Mexico and Guatemala (the Mayas, Toltec, Olmec and some Aztec afterwards).  The Aztecs made tamales for the festival Atamalcualiztli to celebrate the birth of the corn god and Izcalli to pay respects to the fire god.  The earliest versions of tamales were made with corn, pumpkin, beans, etc. and roasted over a fire.  The fillings become more elaborate when Europeans brought lard, chicken, pork, olives, raisins, and other foods with them to the New World.