Book excerpt: Hapgood utilizes ancient maps as concrete evidence of an advanced worldwide civilization existing many thousands of years before ancient Egypt. Hapgood concluded that these ancient mapmakers were in some ways much more advanced in mapmaking than any people prior to the 18th century. Hapgood believes that they mapped all the continents. This would mean that the Americas were mapped thousands of years before Columbus. Antarctica would have been mapped when its coasts were free of ice. Hapgood supposes that there is evidence that these people must have lived when the Ice Age had not yet ended in the Northern Hemisphere and when Alaska was still connected with Siberia by the Pleistocene, Ice Age 'land bridge'.