The inhabitants of what are now Mexico and Central America were

Do you mean before the conquest? Before the Spanish conquest, Mexico and Central America was inhabited by a number of cultures, such as the Aztecs, and the Mayas, which we can call together "Mesoamericans". Their descedants today still sometimes speak the languages they used to speak, for example there are more than 1 million speakers of Nahuatl in Mexico and other countries!