Whether a captive ended up in the Americas or was retained in the region was not only a function of his or her origin, skills, or means of enslavement but also of indigenous conceptions of gender. This chapter shows that constructions of gender roles helped to shape the age and sex structure of the Atlantic slave trade. Understanding the gender structure of the transatlantic slave trade is critical to understanding the societies of the Bight of Biafra and the rest of the Atlantic world. Considering the issue from the broad perspective of contact between the Old World and the New, two salient characteristics of that structure have emerged in the literature. First, as is now well known, males predominated in the Atlantic slave trade, though compared to other branches of pre-nineteenth-century migration, both coerced and free, females and children were well represented. Second, the proportion of African women and children carried across the Atlantic was far from constant or uniform; sex and age ratios varied strongly by region and over time (Eltis and Engerman 1993:308; Eltis and Richardson 1995a). Attempts to explain these broad patterns have generally focused on the economic functions of slaves on both sides of the Atlantic, and especially, on the requirements of the plantation complexes of the Americas, without which a transatlantic slave trade would not have existed. Even though New World planters demanded men, they quickly discovered that enslaved African women had a high work rate.