The Incas
The Incas greatest achievement was their agriculture. Terrace was their farming technique. This is where they cut into the mountain creating huge steps. They were flat so that the Incas could farm on them.
Engineering skills were also very advanced. They had a very complex road system that connected the empire though the Andes Mountains. They had to build through the Andes Mountains so they didn't have to go up and down the Mountains.
The Aztecs
The Aztecs had their achievements in medicine. They would use many herbal remedies to prevent and cure the different illnesses. They had cures for all types of things, one being the common fever. Doctors would suggest their patients to take steam baths regularly so that the heat would clean and relax the patients. When they would sweat, the evil spirits were thought to be leaving them. The Aztec doctors also knew a lot about the human body because they had plenty of bodies to practice on from the war and the sacrifices.
The Mayans
The Mayans achievements was astronomy, it was one of the greatest. They knew how many days were in a year and know the fall and spring equinox. They Mayans built their city sound the pyramid of Kukulan. This is where they demonstrated their knowledge of astronomy. They built 365 steps that lead up to the pyramid of Kukulan, one step for each day of the year. they also demonstrated their knowledge through autumn and spring equinox. Every equinox there would be a snakes shadow that would slither down the pyramid leading to their sacred source of water.
The Olmecs
One of the early achievements were in art. They made fine pottery and beautiful jewelery. The Olmecs also had many sculptures. They would use wood, basalt and jade to make these sculptures. The wooden sculptures were found to be the oldest in Mesoamerica. They would use basalt to make huge colossal heads. The size of these heads were around 5 feet to 11 feet tall. These head were used to represent sacrificial offerings, or the Olmec ancestors.