Thousands of these mounds were discovered in the plains and forestssome up to a hundred feet high, some overgrown hillocks, some conical, others flat-topped. Speculation was rife as to the identity of the moundbuilders. As George Milner shows, research over the past century demonstrates conclusively that Native Americans built these mounds. In a period ranging from 3000 BC to the sixteenth century AD, North American Indians quarried tons...