Yes, Columbus discovered America. It was his coming here that directly led to the awareness of the continents by the rest of the world. The Vikings, if they were here at all, didn't do that, and the previous inhabitants kept the place to themselves. In science, you can find whatever you like in the laboratory, but if you don't publish first, you're not the discoverer, and you don't get the Nobel Prize.
As for the deplorable things that Columbus and his successors did, all of us who live here except those solely descended from those previous inhabitants are the beneficiaries of that, so while we can deplore it, as we should, denouncing its practitioners root and branch doesn't look too good on us. Considering the state of the world, our descendants won't look too kindly on us, either.
So let us celebrate, by the relentlessly logical procedure of closing the post offices, preventing me from mailing packages to B's sister and niece until tomorrow. I will give my thankfulness that the auto repair shop is not closed, and was able to repair and reinstall the flat tire I got yesterday on the freeway: exciting times.
Hobbling on my spare tire over there, I saw a nice indication of the ethnic dominance of this area in the form of front yard signs for school board and city council candidates named Chang, Zhang, and Huang.