The Inca civilization thrived from around 1200 up until the infamous Francisco Pizarro arrived in 1532 and began the Spanish Conquest (Columbia "Inca"). From then on, the Inca's culture was slowly Hispanicized. Their original language was lost altogether and their social organization was extremely disrupted.
However, during the prime of the Inca civilization there was an emperor who required total obedience, but who also looked after his subject's welfare. The state owned almost everything and could draft people to work in mines or on public projects. Priests, government servants, the aged, sick, and widowed were supplied from imperial storehouses. The large royal family formed the nobility, while a highly privileged "Inca class" governed colonies. The Incas also made elaborate tapestries, fine polished pottery, and complex metalwork (Columbia "Inca").
Although the native language of the Incas is known as Quechua, surveys and census reports were recorded on quipus. These knotted strings were bound together on a common cord. This system was long used by the Incas as a tallying device. They even used the quipus as history journals. However, unlike a book, a quipu requires more than the eye to read. One looks at cords of different colors and feels the knots with ones hands to acquire the true information contained in each cord.
It is sad that the Inca culture has been shadowed and slowly lost by modern influence. However, while it thrived, it was marvelous.
From Josh Marcy's, Topher Wilkins' and Adam Tarnoff's ID1 paper.