Who were the earliest Americans? When, how, and from where did they enter and spread across the continent? What is their relationship to modern Native Americans? Anthropologists develop theories to answer these questions based on the evidence they discover. Their theories, and the discoveries that prove and disprove them, are highlighted in this fascinating volume. It is full of awe-inspiring facts and incredible breakthroughs. Readers will feel like anthropologists and archaeologists themselves as they read about bones and artifacts, and what they reveal about the ancient cultures that roamed North America, more than 13, 000 years ago.