In preparing the first edition of this book, I was, with rare exceptions, only able to include material reported prior to 1985. The appearance of this new edition has afforded me the opportunity to update the references and to revise the text accordingly. Among the new finds of the last few years are a spectacular tomb complex of the Mochica (now usually called Moche) civilization in the Sipan Valley of coastal Peru; a cache of enormous Clovis points in Washington State; a remarkably preserved Middle Archaic cemetery, including woven fabric, gourds, and human brains, in Florida; and early Maya centers in northern Guatemala, which show that Maya civilization emerged several hundred years earlier than previously suspected. Recently reported dates from coastal Peru have pushed back the beginnings of monumental construction there, well into the third millennium B.C. Continuing progress in the decipherment of Maya hieroglyphs is bringing individual rulers and their activities into sharp focus, comparable to that of European dynastic histories; in other words, the Maya are rapidly moving from prehistory into history.

The new accelerator mass spectrometry (AMS) method of radiocarbon dating has been producing many reliable dates. A surprising recent development is the possibility, raised by comparison with uranium-thorium dates, that the discrepancy between radiocarbon and real ages may be a few thousand years for materials pre-dating 9,000 years ago; the actual time of Clovis expansion may have been about 11,500 B.C., not 9500 as indicated by radiocarbon.