What we know about the New World is historically recent. The archaeological record shows that what we know about the Maya for example, spans about 120 years, and most of the actual scientific and field record covers about 30 years. We are speaking of a culture with a written language, difficult to translate, yes, but a language nevertheless.
The Incas had the quipus, knotted ropes which we have yet to figure out the meaning of. How about culture in the length and breadth of the Americas; that left sparse individual or collective implements; most did not leave anything.
Here are some recent in-depth articles which you might find interesting.