Many archaeologists believe that men may have first come to North America 40,000 years ago from Siberia and moved south, populating both continents. Here the vestiges of civilizations prior to European explorations provide the basis for an introduction to North American peoples. The author offers her own identities (Old Desert Culture, Archaic people, Burial Mound Culture) instead of using academic labels (e.g. Sandia or Paleo-Indian) but refers to standard groupings later--Eastern Woodland, Plains and Southwest tribes, etc. The probable Eskimo crossing at the same place thousands of years later is included (and physical distinctions indicated) but theories about an Africa-to-South America passage (Heyerdahl) or the more widely accepted South Pacific-to-South America emigration are not. Shimin's illustrations--the familiar blue and pale orange--are perhaps too atmospheric but nevertheless helpful, even on the close-ups on relics. Baldwin (America's Buried Past), Marriott (The First Comers), and Scheele (The Earliest Americans) are all older; in excluding both archaeological names and the discovery procedures this is more suitable for the younger readers intended.