From the late 19th into the mid-20th century millions of people migrated, seasonally or more permanently, to regions where African farmers produced cocoa, groundnuts, coffee, cotton, and palm oil for export. These “cash-crop migrations” occurred mostly under colonial rule, but they were not directed or controlled by Europeans, and were shaped by a history that preceded colonialism. This chapter studies the four major cash-crop migration systems across West and East Africa, centered on Senegal and the Gambia, Ghana and Côte d’Ivoire, Nigeria, and Uganda. We identify the factors in sending and receiving regions that led to the onset, transformations, and eventual decline of widespread rural-to-rural mobility. We find that these systems rose alongside the process of emancipation from slavery, and that they persisted for decades as an effective response to large economic opportunity gaps, given that only a few areas could profitably grow export crops. While cash-crop migrant routes eventually dried up as the agricultural frontier closed and prices for tropical commodities worsened, they inaugurated an era of large-scale, voluntary, long-distance labor migration that continues to define African mobility.