When contracting, European merchants could at least partially observe characteristics such as the health, physical strength, and education of indentured servants. These characteristics, unobservable to us, were likely to influence servitude duration, which is observable to us. We employ a switching regression model to analyze 2,066 servitude contracts from the seventeenth and eighteenth centuries. Servants were positively selected to American mainland colonies in terms of their unobservable human capital and negatively selected to the West Indies. Thus, the relative quality of migrants' human capital may have played a role in the subsequent relative economic performance of these regions.