The thing with Columbus is that he bought into a version of the world-is-a-globe hypothesis under which the planet was a lot smaller than it actually is. That's why he thought Asia was in sailing distance, and assumed that when he'd got Asia when he'd actually reached America.

What's puzzles me is why it ended up with all this stuff about Indians and so forth, when the initial assumption was that they had reached China. Logically speaking the people living there already should have been called Chinese, which would presumably have meant that the newcomers would have been embattled with the Red Chinese hundreds of years earlier than was actually the case.

It'd make more sense to refer to the people descended from the ones who were there first as just plain Americans, and to call the descendents of the newcomers New Americans. But I suppose it's too late now.