One thing that has always intrigued me is how the original natives of the Americas figured out nixtamalization. Nixtamalization is just not something you look at and instinctively say, "I need to do this."
Most of the original people in the Americas grew one variety of corn or another as a staple of their diet and practically all of those used one form of nixtamalization or another. Nixtamalization is the process of adding an alkaline agent of some sort during the preparation of corn (maize), without which corn does not release it's full vitamin content to the human body.
This is why tortillas and tamales taste the way they do. Powdered lime is added to the dough or batter (such as in Indian fry bread). It's interesting to watch the batter for Indian fry bread made from traditional blue corn varieties turn a more pronounced shade of blue when the lime is sprinkled in.
The old native way to make the lime is to bake pieces limestone in a really hot campfire, then pound it to powder using a mortar/pestle arrangement, typically with a hollowed out tree trunk.
Another method of nixtamalization learned from the native tribes is to use wood ash to create a lye solution and pre-soak the corn kernels in it to create hominy, which, when ground up, is that southern US breakfast staple, grits.