 Britain withdrew from slave trade, Brazil abolished slave imports in 1831, and by 1860s most major slave markets of the world had abolished slavery.These developments stabilized the lives and family units of the Sena people and other ethnic groups in the Zambesi valley as well as the rest of Africa.During the scramble for Africa the weakened Portuguese crown leased this region to British companies, which built the railway connections between the Indian Ocean and their colonies, in this case the TZR, Trans-Zambezi-Railway, between Beira and Njassaland/Malawi via Sena.