Mysteries of Sex invites the reader to suspend the belief that men are men and women are women and explore two intertwined phenomena. The book asks first of all just how the dividing line between male and female is drawn—and repeatedly redrawn—over the course of history. That is the “mystery of sex.” Secondly, and as noted in the subtitle, the book explores the historical consequences of making distinctions between things male and female.The pursuit of these questions takes the reader over some five hundred years of American History, from the sixteenth century to the twenty-first. Each of the book’s seven chapters poses another mystery, set in another moment in time. The story begins when Europeans and American Indians first encountered one another, producing mutual bewilderment about alien ways of practicing manhood and womanhood. It concludes late in the twentieth century when another wave of immigration into North America once again dispelled belief that there was one cross-cultural, transnational meaning of male and female.Accounting for the variety and the malleability of sexual differentiation is both an intriguing intellectual exercise and a critical political and humanistic project. To acknowledge the variety, mutability and recurring mystery of sex is to challenge the inequity and misunderstanding that have too long plagued the relations of men and women.