What was the earliest American civilization located along the Gulf Coast of Mexico?

The Olmecs are recognized as the earliest American civilization located along the Gulf Coast of Mexico. This ancient culture emerged around 1400 BCE and is often regarded as the "mother culture" of Mesoamerica due to its significant influence on later civilizations, including the Maya and the Aztecs. The Olmecs are known for their impressive artistic works, particularly the colossal stone heads they sculpted, and for their advancements in societal organization, trade, and possibly the early development of writing and calendar systems.

In contrast, the other civilizations listed, such as the Aztecs, Maya, and Inca, developed later and in different geographical areas. The Aztecs were primarily based in central Mexico, the Maya civilization thrived in areas of present-day Mexico, Guatemala, Belize, and Honduras, and the Inca were located in the Andean region of South America. Therefore, while each of these cultures made significant contributions to the history and development of their regions, the Olmecs hold the distinction of being the earliest civilization along the Gulf Coast of Mexico.