Teotihuacán was a multi-ethnic city, with distinct Zapotec, Mixtec, Maya and what seem to be Nahua quarters. Immigration played a key role in the city’s growth and its variety of ethnicity. This then included ethnic barrios. The well-known Oaxaca (Zapotec) Barrio and the Merchants’ Barrio continue to be the subject of research on the immigrants in Teotihuacán. Due to these barrios, we have found that there was immigrants coming from western Mexico, Oaxaca, the Gulf Lowlands, and central Mexico.