How did the Niger delta city-states participate in the Atlantic slave trade?

During the 17th and 18th centuries, the city-states of the Niger delta became the primary outlets for the Atlantic slave trade in the region. These coastal communities, inhabited by Ijo, Ibibio, and Efik peoples, organized themselves as entrepôts to facilitate the trade, partly as a defensive measure to avoid becoming victims of the system themselves.123

The city-states functioned as intermediaries, controlling the waterways that connected the interior to the coast. They relied on the Igbo and other hinterland populations to supply the enslaved people who were then traded to European merchants in exchange for goods such as cloth, metals, tools, guns, and spirits.312

This commerce spurred significant social and political changes, including the emergence of a new class of wealthy African merchants and the development of the "House" system—a corporate structure that bound freemen and enslaved people together to manage trading operations. The slave trade caused profound economic and political dislocation, intercommunal rivalries, and the forced migration of millions of people. By the 19th century, following the abolition of the British slave trade in 1807, these city-states transitioned to exporting palm oil.3124