Sherbro Island and the surrounding estuary were central to the transatlantic slave trade for much of the 18th century. The island's geography — a maze of rivers, creeks, and mangrove channels — made it ideal for the holding and transfer of enslaved people awaiting shipment across the Atlantic. Several holding sites existed on and near the island, and the Sherbro estuary was one of the major embarkation points along the Upper Guinea Coast.
There are no formal memorials or museums dedicated to this history on the island today, and much of the physical evidence has been reclaimed by vegetation. But awareness of this past is part of what the island carries. Visitors with a serious interest in the history of the slave trade may want to speak with local historians or the community in Bonthe, who maintain an oral tradition around these events. The history of the island's transition from slave trading to legitimate commerce in the 19th century is also notable — Bonthe became a centre for the Krio merchant class who built much of the colonial-era town.