For those of us who love reading about American Indians, there is lots and lots of original literature written by first person observers from the time, including the 17th, 18th and 19th centuries.
Modern scholarship on Native Americans is a joke, it’s just a weapon in the ideological jihad against America by radical faculty. It’s all intended to support the genocide and racism narrative for modern political goals of open borders, redistribution, anti-white racism and ending national self-government.
Got that right; and one of the biggest jokes (in addition to some mentioned in this present article) is what they are now saying was the total population of the Americas, pre-Columbus.
I was a student of Anthropology in the 1960s (undergrad major and grad school special field). It was standard then to put the total population of the Americas at no greater than 10 million. The theory was that low life expectancy and warfare over livable land limited the habitability to that 10m figure. Add to that the propensity toward no-change or slow-change, the valuing of sameness over the generations of prehistory, all mitigated against innovations which might have afforded higher populations.
Look at the PC field of Anthro now. It is agenda-driven, as shown in this article, and they want to say there was a population 10x as high as we assumed 50 years ago. I think the motive is to insist that, without hated industrialization, the earth could still provide for fairly large populations if "only we would be kinder to her". I get nauseous just writing that last fatuous sentence.
My $.02
There also exist nineteenth century photographs of atrocities.
But the fantasy that stone age and bronze age cultures could be pacifist utopias has been an easy sell to the snowflakes.