The Incans were the strongest and largest nation of the pre-Columbian America. Actually general people in that society were not called Inca. Only the Emperor was called Inca or Sapa Inca.
Incan people started to form their big Monarchy under the leadership of Pachacuti. Manco Capac is the first Emperor who formed the small city-state of Cuzco or Cusco in the 13th century. But certainly Pachacuti was the most important Inca emperor during their regime. In 1438 under the command of Great Pachacuti Inca began their greatest expansion. During his period , he along with his son brought a vast area of South America; under the control of Inca Empire.
When Pachacuti became emperor, Cusco was only a small town where Inca lived. But Pachacuti reorganized the kingdom of Cuzco into an empire. He converted his empire ship to a new governmental system which was known as Tahuantinsuyu. In this system there was a federal government and four provincial government. Head of the federal system was Inca. And head of the other provincial government was Inca nobles. Pachacuti is also known to be the creator of Machu Picchu. Though it is not still clear whether it was used as his home or as a any other purpose.
Another key to the success of the Inca was their modern government organization. Pachacuti was the very first man to set up a great empire system and it started to run very well. They had four quarters headed by four Apos, who were just below the King. Every quarter was made up of several provinces run by officials. The system was hierarchical and administered by a well-developed bureaucracy that collected tribute and distributed it. Head of every provinces were the governors. Governors were responsible for his provinces. There were 80 provinces around Inca empire system. Every provinces were made of around 20,000 households. Below each government there were two Curacas, who were in charge of 10,000 households each. Each of these curacas were again in charge of two curacas of 5,000 households. Then curacas (5,000) was the in charge of five curacas of 1,000 households, who were again in charge of two curacas of 500 households. Finally These two curacas (500) were in charge of five curacas of 100 households. Main job of the curacas was to make sure proper function of Mita system. Curacas was playing very important role in Inca empire system.
Inca developed one of the best public works system on those days.Mita was one kind of labor tax. The Incas required all the taxpayers to work for a certain period in each year for the Empire. This labor were called Mita. Local official decide the the turn for individuals efficiently hence reducing the disruption in the lives of the workers and his family.
LAW The Inca government promoted peace among its citizens, there was very little crime, but when a crime was committed the punishment was ruthless. Inca laws were severe and any kind of law transgression was considered an action against divinities. There was no system of imprisonment and offenders were punished so that the penalty was exemplary to the rest of the population. Those who survived a punishment were forced to tell their stories for the rest of their lives, those interested in listening would give them food so basically their survival was based on how engaging and compelling their stories were.
There was almost no crime in the Inca empire because punishment was swift and harsh. If you were caught stealing, for example, your feet and hands would be cut off. If you lived through your punishment, you received a new job. Everyone in the Inca had a job. Your job would be to sit by the gate to the city, or in the plaza, and tell people about your crime. Although the state fed and clothed you, you were suppose to beg for food. That was part of your punishment. This greatly discouraged others from following your example.