Specially trained officials kept records on a quipu, a collection of colored strings that were knotted in different ways to represent various numbers. Scholars think that the Inca, who never invented a writing system, may have used quipus to record economic, bureaucratic, religious, and other information. The Inca then took the quipa and used it with the yupanas, a system of stone grids representing various mathematical values, to make complex calculations.
To unite their empire, the Inca imposed their language, Quechua (KECH wuh) and their religion on the people they conquered. The Inca also created one of history's great road networks. At its greatest extent, it wound about 14,000 miles through mountains and deserts, passing through an area inhabited by almost 10 million people. Hundreds of bridges spanned rivers and deep gorges. Steps were cut into steep slopes and tunnels dug through hillsides. The expanse of the Inca road system was unmatched in the early Americas.
The roads allowed armies and news to move rapidly throughout the empire. At stations set regular distances apart, runners waited to carry messages.
Relays of runners could carry news of a revolt swiftly from a distant province to the capital. Inca soldiers stood guard at outposts throughout the empire. Within days of an uprising, they would be on the move to crush the rebels. Ordinary people were restricted from using the roads at all.
All roads led through Cuzco. People from all the culture groups ruled by the empire lived in the city. Members of a given group lived in a particular part of the city and wore the traditional clothing and practiced the traditional crafts of their region of origin. In the heart of the city stood the great Temple of the Sun, its interior walls lined with gold. Like Inca palaces and forts—and like the temples and other buildings of the Maya and the Aztec—the temple was made of enormous stone blocks, each polished and carved to fit exactly in place without mortar used to secure it. Inca engineers were so precise that many of their buildings have survived severe earthquakes.
How did the Sapa Inca consolidate his power and keep control of his large empire?
Machu Picchu, built at the height of the Inca empire, is a complex located almost 8,000 feet above sea level. It is composed of some 220 structures that were used for agricultural, ceremonial, and astronomical purposes.
The Inca strictly regulated the lives of millions of people within their empire. The leaders of each Inca village, called an ayllu(EYE loo), carried out government orders. They assigned jobs to each family and organized the community to work the land. Government officials arranged marriages to ensure that men and women were settled at a certain age.
Inca farmers expanded step terraces built by earlier Andean peoples. They carved out flat strips of land on steep hillsides and built stone walls to hold the land in place. The terraces the Inca created kept rains from washing away the soil and made farming possible in places where naturally flat land was scarce.
Farmers spent part of each year working land for their community, and part working land for the emperor and the temples. The government allotted part of each harvest to specific groups of people or for particular purposes. It stored the rest in case of disasters such as famine.
The Inca were some of the most skilled metalworkers in the Americas.