In the beginning there was nobody living in the land we today call the United States of America. This should be pretty obvious given the continents of North and South America, which we collectively call the New World for reasons best described as to the victors go the spoils, split off from the rest of our world’s major land masses millions upon millions of years ago, leaving some pretty damn big oceans in between. Given that our ancestors, or at least the ones where if you saw them and said yeah I’d hit that nobody would give you a weird look, didn’t emerge in Africa until only around 300,000 years ago, the reason for this should be pretty obvious. These first humans didn’t even start leaving Africa until some 70,000 years ago, at which point they spread relatively quickly, at least compared to most animals, across Asia, Europe, and Australia over the next 30,000 years.
The world of early humans was not exactly an easy one to live in. The world was in the middle of an ice age which covered huge swaths of the northern and southern hemispheres with giant ice sheets and there were giant wooly versions of many of the animals we have today, not to mention all sorts of big ass predators too. There was also more land than there is today, what with sea levels being over 300 feet lower due to all the water being ice and whatnot. Anyways, All humans lived a hunter gatherer lifestyle, travelling in small bands place to place, staying until food became scarce and then moving on. It was this constant search for new food sources that led our ancestors to leave Africa, where the ice age was causing all sorts of sharp climatic shifts, with formerly wet and fertile areas turning dry and barren seemingly at random.
If you could travel back in time to those early days, once you got over the lack of technology you’d probably notice that these early humans were just like us. They wore clothes, made various tools out of stone and other such easily found materials, had languages, made art, sang, danced, kept domesticated dogs, sat around fires telling stories, and developed various religious and philosophical beliefs. They were smart enough that if you gave one an iPhone, they’d be able to figure out how to use it. If they remained healthy, they could live to a similar lifespan as us, but few ever got the chance given the high probability of if not starving to death at least nearly always suffering from malnutrition, not to mention the fact that their rudimentary knowledge of first aid and natural medicines was rarely up to the task of saving them when they got sick or injured.
One interesting factoid about these early humans, was they were not alone. Aside from the fact that various erect walking ape ancestors and distant cousins were still very much a thing, though quickly dying off, there were also various close cousin species which were at similar levels of development; having fire, tools, clothes, culture, and the such. These included the Neanderthals in Europe and the Denisovans in Asia, both of which left Africa much earlier than humans. When our ancestors discovered these cousins they pretty much fucked and murdered them into oblivion. That’s right, being an asshole has been a human trait since the very beginning. It was pretty much a situation where there was a limited amount of food to go around, and if you had to kill somebody it might as well be the people you find the least sexually attractive. Not great, but that’s just how it was.
Anyways, this constant search for food over time led to many bands of humans moving north, closer and closer to the giant fricking ice sheets where the giant wooly animals lived. Better hunting techniques made these animals a viable source of food, and a full belly was seen as being well worth dealing with uncomfortably cold weather. The ice age was caused by natural variations in the Earth’s tilt and orbit, and as these factors began to normalize somewhat, some of the ice sheets began to retract, drawing people further and further north. Eventually, around 20,000 years ago, the combination of these two factors brought people to Beringia, a surprisingly temperate chunk of land connecting Russia and Alaska which is today under the Bering Sea. These were the ancestors of the Native Americans.