Mayan civilization reaches its peak during this period. There was not a centralized empire, but there were shifting alliances between city states and frequent warfare, similar to the city states of ancient Greece. Major city states included Palenque, Piedras Negras, Uaxactun, Tikal and Copan, among others. While agriculture or farming was the foundation of the Mayan economy, they were also great merchants. Mayan trade goods included cotton, cacao beans (which are made into chocolate), pottery, salt, honey, sea shells and more. Trade routes reached up into urbanized settlements of what is now the southwestern United States, across the Caribbean and up the Mississippi River.

The Mayas made books, only a few of which have survived, using paper made from bark or other plant fibres, and then coated with a fine layer of lime, which acts as both a preservative and whitener. They used 800 "glyphs" or picture-words for writing, something like the hieroglyphs used by the ancient Egyptians. Mayan inscriptions are more commonly found on stone tablets, walls and pottery. Although two million people in Mexico and Central America still speak Mayan, only a quarter of the ancient glyphs have been deciphered. Most of what has been read tells the stories of powerful kings and their wars of conquest.

For the Mayas, the year 2000 happened 3110 years ago! The Mayas had developed the most advanced system of mathematics for the time, and in some ways is still superior to the way we count today. They were very interested in time and space, and their expert knowledge of math allowed the Maya to make highly complex astronomical calculations. We know that the Mayas began their calendar, their year 1, on August 11, 3114 BC, but we do not know what made this date significant (for example, the way the European calendar starts year 1 with the birth of Jesus Christ). That means the Mayan year 2000 on the European calendar happened in 1114 BC.

The city of Teotihuacan, near present-day Mexico City, reached its peak in 500 AD, with a population of up to 150,000 people and occupying an area of 20 sq km. It is still not known who built the city or what language they spoke. It was the most important religious centre in Mexico. Even a thousand years later, when the city was just ruins, the Aztecs called Teotihuacan, "the city of those who have the road to the gods".