The beginnings of the Teotihuacan civilization are shrouded in mystery, as very little is known about their origins. It is believed that the city was founded around 200 BCE, and by 500 CE it had become one of the largest and most influential cities in the Americas, with a population of over 100,000 people. Teotihuacan was located in the Basin of Mexico, about 30 miles (50 km) northeast of modern-day Mexico City.

The city was organized around a grand central avenue known as the Avenue of the Dead, which was flanked by impressive monumental architecture, including the Pyramid of the Sun, the Pyramid of the Moon, and the Temple of the Feathered Serpent. The city's layout and monumental architecture suggest that it was a highly organized and centralized state, with a powerful ruling elite.

The people of Teotihuacan are believed to have been ethnically diverse, with evidence suggesting that the city was a melting pot of different cultures and languages. The civilization had a complex and sophisticated economy, with extensive trade networks that extended across Mesoamerica. The people of Teotihuacan were skilled in agriculture, pottery, obsidian working, and other crafts.

Despite their remarkable achievements, the Teotihuacan civilization went into decline in the 7th or 8th century CE, for reasons that are still not entirely clear. The city was abandoned and gradually fell into ruin, but its influence continued to be felt throughout Mesoamerica for centuries to come.