On the eve of the Spanish conquest, complex societies that sought their legitimacy and identity in the past, and pursued the future through study of that past, dominated the area now known as Mexico. Written records were an important means of securing knowledge of the past and the surviving Mayan and Aztec manuscripts reveal their preoccupation with time and with their place in history. This paper, in seeking to demonstrate that the Mexican peoples were on the verge of developing a unified system of writing, and possibly some form of printing, will examine some of the salient features of those manuscripts and the societies that produced them.