In spite of the large number of civilizations in the Pre-Columbian Americas and their collectively important contributions, certain groups stand out.
First and foremost, The Olmec were incredibly important to the development of Mesoamerica. Their contributions in art, tools, the tortilla (!!!), architecture, and culture in general left a lasting impression on the region for millennia to come. Their influences were so instrumental in developing a culture and way of life for those that would follow, such as the Toltecs and eventually the highly-studied Aztecs, that the Olmecs are known as the “mother culture” of Mexico.
Another “group” that was important to the era was the inhabitants of the Andes that collectively gathered (and permanently settled) in Chavin de Huantar in what is today central Peru. While the permanent settlers (the Chavin people) “never surpassed 3000”, the highly organized ritual center that was Chavin de Huantar was likely a site for many pilgrimages from the Andes region. Because of its predating the later civilizations of the Moche, Wari, Nazca, and Tiwanaku in the vicinity, Chavin de Huantar was key to further social organization and trade networks that would enivitably inhabit the area in spite of its small size. The Chavin are particularly important to these other groups and ultimately, the Incas, because of their mastering of the extreme altitudes of the Andes, a feature of the are that has proven to be somewhat of a double-edged sword, yielding crops that varied their diet greatly at different altitudinal zones, while making everyday living more harsh and inhabitants vulnerable.
The Maya were undoubtedly one of the most important and “great civilization[s] of the Classic Era”. By far, their largest contribution to the natives that would follow was their written, phonetic language of glyphs. This was also quite significant in terms of our ability to study the Maya and Pre-Columbian civilizations. They effectively preserved a great deal of information for future generations. With it, scholars have been able to study their culture and way of life at great length. The language of the Maya has been instrumental in fostering developments in study of other cultures in the region as well. Because we know certain things about Maya society and culture, we can consider these concepts when faced with challenges and unknowns about civilizations with similar cultures and realities. The Maya also had an advanced numbering system, in which they developed the concept of “0” completely independent of outside influence or prexisting knowledge. Their mastery also extended into warfare, landholdings and agriculture.