From 1895 to 2015, the Mexican census has painted a picture of Mexico’s people, providing details about languages spoken (Spanish, foreign and indigenous), religion, education, literacy, employment and migration. From the beginning, the Mexican census provided details about indigenous languages spoken by its citizens. However, in the first half century, it is possible that there were undercounts of indigenous language speakers because some may have failed to declare their language status for fear of affecting their position within the community. In addition, poor communications channels with rural, isolated indigenous communities may also have caused an undercount of the indigenous people.

The Mexican State of Hidalgo is located in Mexico’s Central Plateau and shares common borders with San Luis Potosí on the north, Puebla on the east, Tlaxcala on the southeast, the state of Mexico on the south, Querétaro on the west, and Veracruz on the northeast. Politically, Hidalgo is divided into eighty-four municipios and has a surface area of 20,813 square kilometers, or 1.1% of the national territory, making it the twenty-sixth largest state of Mexico.