<font face="Verdana, Arial" size="2">Originally posted by InFa:
Actually... there were a number of people who knew the world was not flat well before Christopher Columbus ever sailed the ocean blue. Just to shatter yet another common knowledge 'fact'. It's funny how little we really 'know'.
Just when you thought it was safe.</font>
Pretty much the only group of people who thought the earth was ever flat were the Europeans. Romans, Greeks, you name the group and they depicted the earth as a sphere (all be it a very small one). Most ship navigators would also have been aware of the shape of the earth.
This was purely for argument to laymen and it became part of the story.
Coincidentally one of the first cargos back to Europe was native American slaves. The trade stopped after a couple of boat loads though as they were found to die to quickly (no immunities to European diseases). Talk about a double edged sword, the diseases that are killing you in North America are preventing you being turned into slaves.