OP, you're going to have to be more specific because there are thousands of books collectively on the topics you bring up that plenty of people (more than nobody) talk about. Semantics aside now, I assune your actual question is: why is pre-English colonization of North America not as commonly taught in US schools?

And the answer to that question in it's shortest form is because US Americans are taught history primarily through a teleological, nationalist lens. What I mean by this is that US history is largely teleological in that too many curriculums only focus on a chain of events that can be cleanly drawn from the American Revolution backward in time within the prism of US history specifically (usually beginning with the English settlement of Jamestown since that was England's first significant colonial foothold in what would become mainland US territory.) Since the foundational colonies were predominantly English, and those colonies contributed most directly to nationhood/statehood, that is the history that is focused on. It's not ideal by any means, but these kinds of nationally-oriented regional scopes of history are quite common.

But you also bring up an important perspective (or lack thereof) here. Why are Iberian explorers (and only those relevant to what became mainland US) so important to you specifically? What exactly does exploration contribute to the emergence of complex society centuries later? What about the Indigenous peoples that De Soto bulldozed through on his psychopathic rampage? Or the Indigenous peoples of Florida that were enslaved and sent to the Caribbean? Ditto for those (including Tisquantum aka 'Squanto' who were captured and enslaved by Thomas Hunt's English crew way out in the Northeast well before the "First Thanksgiving." And why place an emphasis on Thanksgiving at all when it wasn't made important until Abraham Lincoln made it a holiday hundreds of years later. Why should we care so much about people who "discovered" natural landmarks that were already so well known to the people who already lived there? Why should we care about North America at all when the Caribbean was the heart of western empire well past the 1500s?

The point is, plenty of historians and others do write, talk, and teach about these things, but since they don't fit so easily into the US nationalist narrative of progress, people are less likely to retain the information or see any relevance. This very thinking is embedded into your own view (and I say this respectfully) just by your emphasis on explorers and ither violent (but canonically 'great') figures alone. The discourse is out there. It is what informs the platform for replacing Columbus Day with Indigenous Peoples' Day. It is the basis of the exploding field of Atlantic History. It is certainly discussed widely at the collegiate level at least, but only briefly since there is just so much information to cover.

I say all this not to bash, but to encourage a different approach, that 16th-century American history does matter, but for very different reasons than the ones you posit. Indigenous history is history, and what Native Americans were doing alone impacted the developments of colonialism significantly. The entrance of the Iberians, not just to North America, but especially to the Caribbean, Cental and South America also had an important ripple effect on where the English, Dutch, and French could attempt to colonize. Indeed, by the 1500s, certain Caribbean islands had both already been entirely exterminated of Native people and replaced by pockets of free Black societies as Spanish colonization moved past the Caribbean to Venezuela, Mexico, etc. Point being, in order to see the importance of Indigenous people, Atlantic slavery, and Iberian colonization (all of the 1500s) we need to think much broader than "what would become the US" and "who contributed to the US." Because that is the kind of teleological thinking that your question exposes in the first place.

If I may suggest one book on 1500ish American history, check out Sam White's A Cold Welcome: The Little Ice Age and Europe's Encounter with North America. Yes, it is about climate, but it is also one of the best books to cover a large amount of these early episodes with up-to-date interpretation. If you would like to branch out further, check out David Wheat's Atlantic Africa and the Spanish Caribbean, 1570-1640.

Hi there! You’ve asked a question along the lines of ‘why didn’t I learn about X’. We’re happy to let this question stand, but there are a variety of reasons why you may find it hard to get a good answer to this question on /r/AskHistorians.

Firstly, school curricula and how they are taught vary strongly between different countries and even different states. Additionally, how they are taught is often influenced by teachers having to compromise on how much time they can spend on any given topic. More information on your location and level of education might be helpful to answer this question.

Secondly, we have noticed that these questions are often phrased to be about people's individual experiences but what they are really about is why a certain event is more prominent in popular narratives of history than others.

Instead of asking "Why haven't I learned about event ...", consider asking "What importance do scholars assign to event ... in the context of such and such history?" The latter question is often closer to what people actually want to know and is more likely to get a good answer from an expert. If you intend to ask the 'What importance do scholars assign to event X' question instead, let us know and we'll remove this question.

Thank you!