A duplicate of a Chinese map from 1418 calls into question the European discovery of America. There are authenticity issues because the map is actually a reproduction from the 1700’s. Much of the recorded history surrounding Zheng He’s voyages has been destroyed over the years by other Chinese dynasties, so we’ll probably never know all the details — there was a recent National Geographic feature about his voyages. Regardless of the map’s authenticity, if the Chinese were capable of exploring Africa, and Austrailia, I don’t doubt that they were able to reach the Americas.