Late 18th Century–1880s: (The Eastern African Slave and Ivory Trades Expanding as the Atlantic Trade Declined: Zanzibar as the Dominant Commercial Power, Car…

Late 18th Century–1880s: (The Eastern African Slave and Ivory Trades Expanding as the Atlantic Trade Declined: Zanzibar as the Dominant Commercial Power, Caravans Reaching Lakes Tanganyika and Victoria by the 1840s, Buganda as a Base for Arab Traders, the Nyamwezi as Renowned Porters, and the Kamba as Middlemen): While Atlantic Africa was undergoing its transitions from slave trade to legitimate commerce, eastern Africa experienced a strikingly different trajectory. From the late eighteenth century onward, the eastern African interior was linked to the international trade of the Indian Ocean, the Arabian peninsula, and the Persian Gulf via the Swahili city-states of the coast. At the same time as the Atlantic slave trade was in gradual decline, the eastern African slave and ivory trades were actually expanding rapidly. The escalation was closely linked to the economic system controlled by the sultanate of Zanzibar, which through the nineteenth century was the dominant commercial power on the Kenyan and Tanzanian coasts, serving as a transit handler for ivory and for the deportation of captives while employing enslaved people on its own spice plantations. From the early nineteenth century, Zanzibari merchant caravans began penetrating inland in search of captives and ivory, reaching Lakes Tanganyika and Victoria by the 1840s, and some penetrated even further into the forests of eastern Congo where they carved out loose trading-and-raiding commercial empires. African states and societies became deeply involved in this expansion: the kingdom of Buganda became a base for Arab traders and a major supplier of captives and ivory; the Nyamwezi of central northern Tanzania became renowned as caravan porters, guides, and traders; and the Kamba of southern central Kenya were important middlemen along a trade route of growing importance.