Columbus didn't "Discover" anything. Seriously. The NA Continent was already discovered.

[Revanchist]

1. One could argue the point

that Columbus "discovered" the existence of the American continents in the sense that the majority of the European countries were unaware of their existence and it hadn't been visited by the Norse cultures for around a hundred years so they might of forgotten about it also. Then again, an argument could be made that Columbus accidentally stumbled into the region while attempting to find an easier trade route to Asia and it was just dumb luck.

Edit:

I guess I relate it to the "discovery" of a new plant or animal species, just because a large part of the population didn't know about it before does not mean it did not exist prior to it being found and there were probably indigenous people who knew about it, but it's called a discovery because it is newly introduced to a large portion of the population. Because we (as in America and Europe) tend to base history around what is important to white Europeans I can understand why they claim that Columbus discovered America, even if it is not entirely the truth.