Amerigo - Is he responsible for the US?

This is one of those difficult questions: Who found America? And what was it doing hiding in the first place? I read today that before the Spanish 'found' America, the US had no horses or cattle. It was in a book so it must be true. But can that really be true? What the fuck was wondering around the huge states of the US up until then? Maybe the book was just being nit-picking and chose to ignore animals like buffalo, I don't know.

But, of course, Amerigo was Italian. So how come the Spanish got there first but failed to be recognised as the original discoverers? My theory involves bribes, something the Italians are famed for. Alledgedly...