Admiral Zheng He's last daring global voyage (from 1431) was traced by Chinese historian and author Dr Sheng-Wei Wang. Meticulously studying ancient Chinese texts, ocean current flows and various archaeological finds, she posits that the Admiral may have reached Cape Breton Island in the Gulf of St. Lawrence, before making his way on small river boats to what is now the Cahokia Mounds State Historic Site in the central Mississippi Valley.
If so, the Admiral would have discovered the New World some six decades ahead of Christopher Columbus (1492).
Dr. Wang's findings are laid out in her fascinating scholarly work "The Last Journey of the San Bao Eunuch Admiral Zheng He". She invited me for a Book Review, which is appended below.
Download The Last Journey of the San Bao Eunuch Admiral Zheng He