Over the course of his 30-year journey, Thompson has written five books, all self-published, detailing what he believes to be conclusive evidence that, long before 1492, the Americas were explored repeatedly -- by the ancient Chinese, Venetians, Egyptians, Romans, Vikings, Irish, English and who-knows-who-else. He argues, for example, that a Chinese admiral named Zheng He, commanding a fleet of Chinese junks in the early 1400s, explored the coasts of the Americas. He believes that Marco Polo sailed with the Chinese into the Strait of Juan de Fuca and perhaps into Puget Sound in the 13th century. He is convinced that...