It's my first thread on this forums, and this type of question have been asked many times. But what if the Native Americans had the things would advance them to challenge the Europeans such as:
- Immunity to Old World Diseases: In the OTL, diseases such as smallpox, measles, typhus, influenza, diphtheria, bubonic plague and other diseases were estimated to wipe out 90% of the native population of the Americas. In the ATL, the Native Americans have it due to having contact with primitive, benign versions of diseases, obtained genetic immunity to several Old World diseases.
- Existence of Horses: In the OTL, the American horse went extinct at the end of the Pleistocene due to hunting by the Paleoindian people. In the ATL, some pockets of horses in parts of America survive, allowing them to thrive and expand.
- Metallurgy: In the OTL, metallurgy was limited to the production of gold and silver as well with limited amounts of iron. In the ATL, several Native American tribes learn how to smelt iron, copper and produce bronze.
- Invention of the Wheel: In the OTL, the wheel was limited to children's toys in Inca people and other places. In the ATL, the invention of the wheel spreads all over the America, in independent ways and manages to build carts and carriages
- Seafaring and Navigation: In the OTL, navigation in bodies of water was limited to canoes. In the ATL, Native Americans build boats and learned navigation the level of Polynesians and Phoenicians.
- Increased domestication of plants and animals: In the OTL, Native Americans domesticated several plants and animals as food sources. In the ATL, they increased the number of species that can be domesticated in theory such as buffalo.
- Survival of the Pleistocene Megafauna: In the OTL, the megafauna of the Pleistocene went extinct due to human hunting and climate change. In the ATL, megafauna species like Mastodon, Californian tapirs, shrub-ox, Camelops, sabertooth salmon, Pleistocene carnivores and the 13 extinct species of pronghorn survive.
- New World Diseases: In the OTL, the only confirmed New World disease is Syphilis. In the ATL, there are several New World diseases such as equine influenza, cocoliztli and other ailments exist due to interaction with animals.