That map is mentioned in the opening sentences of 1421: The Year China Discovered America, which is on my stack of books to review. (Perhaps soon. Nephew has birthday pizza party not far from the Mitchell International station. Train trip less stressful than driving ...)
Columbus reputedly discovered the New World in 1492 but Admiral Zheng He may have got there 70 years earlier.
A copy of his map of the world, dated 1418, is about to be unveiled to the public in Beijing and at Greenwich's National Maritime Museum.
I have glanced at the book which offers some speculation about the Chinese origins of the Newport Tower, which has been offered as evidence of all sorts of settlements, although so far nobody has commented on similarities between its base and the base of New Haven Railroad interlocking towers. Perhaps some fieldwork for this summer?
And now for some speculation ... (why should this night be different from any other night?) The North America chapters of 1421 suggest Chinese intercourse with and Chinese influence on the Native peoples of Rhode Island and southeastern Massachusetts. Was memory of the civilized interaction between Chinese and North Americans one cause of the initial good relations between Puritans and North Americans two centuries later. Must read more and report.