So far all of the "real Americans" I've addressed here happen to come from North America. However, there is a whole 'nuther America down south, and that it has its own history of "don't-call-them-Indians."
The 1926 BOMBA book-series begins the history of the juvenile jungle-hero in the forests of South America, though eventually Bomba took his act to Africa. These days the character is best known through a series of black-and-white B-films, mostly from the early fifties, and these too were supposed to be somewhere in South America, though often the attire of the natives looked like they'd emigrated from Polynesia.
For a couple of years in the late 1960s, DC Comics published seven issues of a BOMBA THE JUNGLE BOY comic, all of which took place in a fantasy-version of South America.
Though the series had no support-characters in the first two issues, with issue #3 artist Jack Sparling came onto the title. He would finish out the series, and in the process he gave Bomba a sexy girlfriend who wore a Polynesian dress but talked like a modern teen.
Bomba faced a handful of Indian enemies, but only one was somewhat memorable. Krag, introduced in the last two issues as part of a never-concluded storyline, was a bulky fellow who had been born in some sort of Atlantis-like city before the rise of real history. For his two appearances he unleashes various types of science-or-magic on the modern world. Bomba fights him, Krag escapes, and the series ends with the hero pursuing the villain-- at which point I assume DC lost (or chose to lose) the license to the Bomba property.
