 The African-American population is concentrated in the southern states and urban areas.In the establishment of the African diaspora, the transatlantic slave trade is often considered the defining element, but people of African descent have engaged in eleven other migration movements involving North America since the 16th century, many being voluntary migrations, although undertaken in exploitative and hostile environments.In the 1860s, people from sub-Saharan Africa, mainly from West Africa and the Cape Verde Islands, started to arrive in a voluntary immigration wave to seek employment as whalers in Massachusetts.