The Aztecs: The American Indian people known as the Aztec ruled a large empire in what is now Mexico. When the Spaniard Hernan Cortes reached the Valley of Mexico in 1519 he found a splendid city standing on an island in a lake. At this time the Aztec civilisation was the most advanced in North America.
The Mayans: For hundreds of years before the Spanish arrived in Mexico and Central America, the Maya possessed one of the greatest civilisations of the Western Hemisphere. The Mayan civilisation was at its height between about ad 250 and 900 and then began a rapid decline. The reasons for this decline are still unclear.
The Incas: The Spanish conquistadors reached Peru in 1532. They found a vast empire of Quechua-speaking people called the Incas. Their vast territory, that extended along the Pacific Coast, was ruled through a highly organised government. Many remains of the Inca civilisation can still be found scattered over the central highlands of the Andes.
Britannica Online, 2020