I'm not a historian, so the way I am framing these questions is probably not the best. Also, this question is based-off my knowledge of how it has been in Canada, though I know it is similar in the US. Basically, when Europeans arrived in what is now known as the Americas, they thought it was India, so they called them Indians. But surely, after some years, at max a decade, they figured out it was not India. It hard for me to believe they didn't. And *yet*, for centuries, the people on these lands were called "Indians" and referred to as "Indians". In Canada, we had (and still have in place) the Indian Act in 1876. The department Indian Affairs (that then became Indian Affairs and Northern Development) only changed to "Aboriginal Affairs and Northern Development Canada" in 2011. (Now there are two departments, both using the word Indigenous.) So, all that to say, why? Were the colonizers and settlers too lazy or didn't care to use a different name, so they stuck to something inaccurate?