To my understanding it is fairly well accepted that Vikings discovered and established settlements in North America well before Columbus' expedition. Is there any evidence that their knowledge of this landmass spread significantly throughout Scandinavia and Europe at large between the 11th and 15th centuries?
Sorry for just posting some links to my (and other's) previous posts in this subreddit, but this is really one of the most FAQ:
(Added): I'm of course willing to answer some of follow-up questions from OP, though.