The article examines the campaign against the white slave trade between the late nineteenth and the first half of twentieth century. It focuses in particular on the ways in which it intersected with the emergence of a global prostitution market. The article argues that “the white slave trade” was a deeply racialized construct, which mobilized Western public opinion around the theme of forced prostitution, both domestically and in the colonies, and in the countries of arrival of the great migratory flows. By examining the measures used by international police forces and other organizations to combat the white slaves trade, the author investigates the extent to which they resulted in measures of control of women’s mobility.