Before 1492, Native American societies like the Aztecs, Incas, and Mayans flourished in North and South America. The Aztecs built the city of Tenochtitlan in Mexico and practiced human sacrifice to their sun god. They collected tribute from defeated tribes. The Incas built a large empire in the Andes Mountains with well-organized cities and infrastructure. They were conquered by Spanish conquistadors like Francisco Pizarro in the 1530s. The Mayans rose to power in Mesoamerica between 250-900 AD, establishing cities, advanced mathematics and an accurate calendar, but their civilization declined by 1500.