The Mexico Documents Collection is a result of combining several smaller artificial collections into one in order to improve organization and facilitate access. The collection chronicles the history of Mexico from Spanish rule to the Mexican Revolution. The material has been arranged chronologically into four series: the Colonial Period to Mexican Independence to the Mexican-American War, the Mexican-American War to the Mexican Revolution, and documents with unknown dates. The bulk of the collection is from the period from Mexican Independence to the end of the Mexican-American War (1825-1849).

The documents primarily consist of personal and official correspondence, government orders, decrees, and announcements of Mexican officials. Notable individuals include Santa Anna de Lopez, Jose Joaquin de Hererra and Porfirio Diaz. Additionally, some materials document American military actions in Mexico during the Mexican-American War. Lastly, there are an assortment of documents chronicling religion in Mexico as well as business and land transactions.

Many of the documents have English translations available as well as biographical information.