At the time of Columbus's arrival in the Americas, the dominant civilization in the area of present-day Mexico was the Aztec Empire, also known as the Mexica civilization. Their capital city was Tenochtitlan, located on the site of modern-day Mexico City. The Aztec Empire had an advanced civilization with significant developments in art, architecture, agriculture, urban planning, and religious beliefs.
It's important to note that the term "America" was only applied later to refer to the continents as a whole, and its usage did not exist during the time of Columbus's voyage.