1–400 CE: (The Upemba Depression as a Major Production Center — Bantu-Speaking Lands in and Around the Upemba Depression Through Which the Lualaba River Flow…

1–400 CE: (The Upemba Depression as a Major Production Center — Bantu-Speaking Lands in and Around the Upemba Depression Through Which the Lualaba River Flowed Becoming Major Producing Areas of Iron, Iron Goods, and Salt by the Early First Millennium CE, Both Kinds of Products Traded Northward Along the Lualaba and Lomami Rivers into the Central Congo Basin Networks, and the Independent Invention of Copper Smelting in the Copper Belt by Ironworking Bantu People South of the Upemba Depression): Already in the early first millennium CE, the Bantu-speaking lands in and around the Upemba depression, through which the Lualaba River flowed, had become major producing areas of iron and iron goods and of salt, with both kinds of products being traded northward initially along the Lualaba and Lomami Rivers into the networks of the central Congo basin. Then, developments in the first four centuries CE added a new factor to these resources. Ironworking Bantu people living south of the Upemba depression, at the southern edges of the Congo basin, took advantage of the rich deposits of copper ores in the region of southern Congo and northern Zambia — the area that came to be called the Copper Belt in the twentieth century — and independently invented copper smelting in that region. From the miners and smelters of this region, copper passed northward along the rivers of the Congo basin as well as southward through the Zambezi River basin. Iron, salt, and copper — three commodities, all produced by African peoples using African technologies, all flowing through African river networks. The Upemba depression was the industrial heartland of the Congo basin commercial revolution, and its products fed a continental system of exchange that the standard world history curriculum does not know exists.