This is a common understanding now, to observers who are removed by hundreds of years, but from the primary sources I’ve read, I’m not convinced this is fact. There’s quite a lot of evidence that people living in the time viewed indigenous Americans much the way modern racists view people of color — which is to say they are regarded as people of generally equal capacity in day-to-day interactions, but then labeled as inferior or undeserving of rights when those rights conflict with the material desires of the dominant culture.
The Iroquois Confederation, for instance, was one of the models used by our founders to design the new American nation post-Revolution. Many of the native tribes in the Northeast lived in relative harmony with European settlers — though we should remember that “harmony” was always built on an implied threat of violence should Europeans not get what they want.
By the mid- to late-1800s, the dynamic had certainly shifted so that many involved in westward expansion regarded Indians as savages and barbarians — but that sentiment appears to grow from conflict over material interests, not vice-versa. We see the same, for example, from Andrew Jackson in the early 1800s — Jackson was a racist barbarian, but he was also a land speculator with a financial interest in deposing Indian tribes from land reserved to them by treaty. And again, the Declaration of Independence refers to Indians as brutal savages, but specifically in making a case for independence, driven by desire for profit.
It’s generally held as fact by many historians that the vicious racism white Americans hold against black people is an intentional product of centuries of chattel slavery — that in order to win the support of a southern white population, the VAST majority of whom were not slaveholders themselves, the slave-holding authorities in the US South intentionally spread and perpetuated myths about white superiority. Certainly if we go back in human history, even as far as Classical antiquity, we don’t see the same hatred from white Europeans toward black Africans — it is not a “natural” product of human interaction, it is something intentionally cultivated and taught in support of financial interests.
