In about 1733, Izuogu Mgbokpo, an Aro merchant from Arochukwu, in the Cross River region of what is now southeastern Nigeria, settled his people, or ndị (a generic term for offspring, henchmen, followers, clients, and slaves), on a major trade route located some 30 kilometers west of the upper Imo River in the densely populated central Igboland. Called Aro-ndi-Izuogu (Izuogu's people's Aro, conventionally written as Arondizuogu), this settlement eventually became the largest and most populous Aro settlement. Other Aro merchants soon established settlements farther northwest and in the densely populated part of Ibibioland south of Arochukwu. These merchants were part of an intricate network that accounted for the huge increase in the numbers of captives leaving the Bight of Biafra after 1740. Neighboring people supplied the Aro with produce, captives, and some porterage services, while the Aro, in turn, provided foreign goods, indicating the extent of the region's entanglement with the emerging world economic system. Among these goods, guns and gunpowder came from various European centers, “george” cloth from the Netherlands and most other cloth from India, while tobacco was being produced in the Chesapeake Bay region in today's United States, principally by Biafrans who had been exported as captives of the overseas traffic.

The Atlantic slave market provided attractive profits, but the Aro always ensured that they retained within their group many of the people they traded. As a small group, the Aro concentrated on group expansion and depended economically on slaves as both merchandise and laborers.