This paper explores new roles that traditionally rural kinship networks organized around the marriage institution might play in improving labor market outcomes in urban Africa. Using new data from Kisumu, Kenya, and controlling for selection into marriage, we find that marriage significantly increases employment levels and incomes in our sample of migrants. At the same time, marriage increases the remittances that migrants send to the extended family, consistent with the view that the benefits of the network come with additional social obligations. These obligations appear to be borne disproportionately by high-ability individuals, who consequently defer marriage. The negative selection into marriage that we uncover has consequences for the future viability of the urban networks, with implications for long-term growth and distribution in this economy.