In essence, the hall of Mexico and Central America is dedicated to the archaeology of Middle America. Middle America is a geographic region that encompasses the area between the northern border of Mexico and the southern border of Panama. Mesoamerica is a culture area whose inhabitants developed a shared set of traits including corn-based agriculture and general ideas about the supernatural world. And, it is an area where state-level societies developed. The exact geographic boundaries of Mesoamerica shifted over time. The northern limit was a few hundred miles north of Mexico City while the southern limit included parts of Honduras and Nicaragua. Two modern geographic areas in this hall, Panama and Costa Rica, lie outside of the boundaries of Mesoamerica. In these regions complex societies called chiefdoms developed but state level societies did not.
Mesoamerica's diverse topography led to the emergence of many different ethnic groups. An ethnic group usually speaks the same language and follows similar social norms or behavior. Ethnic groups were in contact with one another and maintained economic and political relationships. It is important to note that archaeologists can't always be sure if the ancient people of a given region spoke the same language or belonged to the same ethnic group as a region's modern indigenous inhabitants. In places such as the Oaxaca Valley archaeologists are certain that ancient and moderns populations spoke Zapotec. In other places migration led to the displacement of some groups by others. Archaeologists are not sure of the language spoken by the inhabitants of the Classic period city of Teotihuacán. In the Postclassic period, the Nahaua were the predominant ethnic group but they are thought to have moved into Central Mexico from the north sometime after 700 CE.