The Aztecs of Mexico and the Inca of Peru both had great empires. There were many similarities between the two along with many differences. The Inca had built a vast civilization spanning more than 2000 miles north to south. The Inca used a network of roads and bridges to keep their civilization connected and used a messenger system where runners who understood the verbal language would run all over relaying messages to and from the leader. The inca had no real written language but they did develop a number system that they used to keep records. To do this they used what was called a quipu. This device was used to keep track of many things ranging from their calendar to economic output. It was even used to take a census of everyone living in the civilization, which had grown to about 12 million people.
The Aztec are remembered for their very gruesome human sacrifices where they would make the human sacrifice walk up the huge stairway of the temple of the sun where at the top they would have their heart cut out of them and placed in a statue of a god and then the priest would kick the corpse down the stairs to the family of the warrior who captured him so they may feast on his body. The Aztecs also developed their empire on a small island in the middle of a lake. They named the city Tenochtitlan and attacked neighboring settlements to force them to join their society and for sacrifice.
Both of these civilizations contributed innovations to history. The Inca contributed with the rope bridge, A footbridge that was built across canyons to shorten traveling periods. These bridges were constructed by stretching rope across the gap and securing it. Then planks of wood were tied across the bottom to walk on. The bridges were very important for keeping their vast road network connected. They were also very effective since the Inca did not use wheeled transportation so the only thing crossing the bridge was people and maybe livestock. Rope bridges were also very...