My nephew apparently got told off by his teacher for pointing out that the Vikings indeed were the first Europeans to land in America, centuries before Columbus did (and if they were talking about who discovered it, well there were people already there long before even the Vikings arrived).  But honestly, it’s not like this is a recent discovery or anything – I believe it’s been known for quite some time that the Vikings visited before Columbus stumbled on it.  Hell my dad, who grew up in the 1940′s, even remembers being taught about it.