Did the Chinese reach America before Columbus? That controversial claim was made (fairly convincingly, to my mind) by Gavin Menzies in his book 1421: The Year China Discovered America. Since the book was published in November 2002, Menzies has continued to marshall evidence, but no Chinese map of the Americas predating Columbus has yet been found. In the aftermath of China’s age of exploration, there was a reactionary closing of the country, and all the ships and maps were carefully destroyed.
That’s why the BBC report on the unveiling of this new map, which its author claims was made in 1763 as a copy of a 1418 map, is so significant. Of course, even if this map does turn out to be from 1763, that’s not proof that it was really copied from a 1418 map. Nevertheless, it would certainly add an interesting new piece of evidence to the growing pile.