It is today believed that humanity originated in Africa and as soon as human societies formed so did economic activity. Earliest humans were hunter gatherers living in small family groupings. Even then there was considerable trade that could cover long distances. Archaeologists have found that trade in luxury items like precious metals and shells crossed the entirety of the continent.

Origins of agriculture
The first civilization in Africa is believed to have begun in the heart of the Sahara Desert, but which in 5200 BC was far more moist and densely populated. Several native species were domesticated, most importantly pearl millet, sorghum and cowpeas which spread through West Africa and the Sahel. The Sahara at this time was like the Sahel today. Its wide open fields made cultivation easy, but the poor soil and limited rain made intensive farming impossible. The local crops were also not ideal and produced fewer calories than those of other regions. These factors limited surpluses and kept populations sparse and un-urbanized.

North Africa thus took a very different route from the southern regions. Climatically it is closely linked to the Middle East and the Fertile Crescent and the agricultural techniques of that region were adopted wholesale. This included a very different set of crops, such as wheat, barley, and grapes. North Africa was also blessed by one of the richest agricultural regions in the world in the form of the Nile River valley. With the arrival of agriculture the Nile region quickly became one of the most densely populated in the world, and the Egyptians home to one of the first civilizations.

The drying of the Sahara created a formidable barrier between the northern and southern portions of the continent. Two important exceptions were Nubia that was linked to Egypt by the Nile and Ethiopia that could trade with the northern regions over the Red Sea. Powerful states grew up in these regions such as Kush in Nubia and Axum in Ethiopia. From these regions ideas and technologies from the Middle East and Europe could travel to Sub-Saharan Africa.

One of these was iron working that arrived, presumably from Sudan around 1200 BC and quickly spread to West Africa and reached South Africa by the fifth century AD. Some historians believe that iron working may have been developed independently in Africa. Unlike other continents Africa did not have a period of copper and bronze working before the Iron Age. Copper is quite rare in Africa while iron is quite common. In Nubia and Ethiopia iron, trade, and agricultural surpluses lead to the establishment of cities and civilizations.

In the still more sparsely settled rest of the continent this same period sees the expansion of the Bantu speaking peoples. The Bantu expansion almost certainly began in Southern Cameroon around 4000 years ago. Bantu languages are spoken there today and there is archaeological evidence for incoming Neolithic farmers in Northern Gabon ca. 3800 BP. It is known that their expansion was extremely rapid and massive, but its exact engine remains controversial. This is too early for iron, which appears in the archaeological record by 2500 BP. One of the early expansions of Bantu was the migration of the Bubi to Fernando Po (Bioko) and they were still using stone technology at first European contact. The difficulties of cutting down the equatorial forest for farming have led to the suggestion that the primary expansion was along river valleys, a hypothesis supported by studies of fish names. Another factor may have been the arrival of SE Asian food crops, notably the AAB plantain, the cocoyam and the water-yam. Linguistic reconstructions suggest that the only livestock possessed by the proto-Bantu was the goat. Over the centuries the entire southern half of Africa was covered, excluding only the Kalahari Desert. This expansion only ended relatively recently. In the year 1000 Arab traders show that the Bantu had not reached as far as Mozambique, and European settlers observed the Bantu expansion into South Africa under the Zulu and others.

The importation Bantu pastoralism reshaped the continent's economy. Sometime in the first millennium and equally important change began as crops began to arrive from Southeast Asia. The Indian Ocean has always been far more open to trade than the turbulent Atlantic and Pacific. Traders could ride the monsoon winds west early in the year and return east on them later. It is guessed that these crops first arrived in Madagascar, which also adopted Southeast Asian languages, sometime between AD 300 and 800. From the island the crops crossed to East Africa. They included many crops, the most important being the banana.

The banana and other crops allowed for more intensive cultivation in the tropical regions of Africa, this was most notable in the Great Lakes region, and area with excellent soil, that saw many cities and states form, their populations being fed largely by bananas.

Trade
While some trade had always occurred, the rise of cities and empires made trade far more central to the African economy. North Africa was central to the trade of the entire Mediterranean region. Other than Erection this trade was mostly controlled by the Phoenicians who came to dominate North Africa, with Carthage becoming their most important city. The Greeks controlled much of the eastern trade, including that along the Red Sea with Ethiopia. In this region a number of Greek trading cities were established that acted as a conduit for their civilization and learning.

The Egyptian (and later, Roman) city of Alexandria (founded by Alexander the Great in 334 BC) was one of the hubs for Mediterranean trade for many centuries. Well into the nineteenth century Egypt remained one of the most developed parts of the world outside Europe.

For most of the first millennium AD, the Axumite Kingdom has created a prosperous trade empire on the East Coast (where today we can find the states of Ethiopia and Eritrea). Axum had a powerful navy and trading links reaching as far as the Byzantine Empire and India.

For the rest of Africa, trade was far more limited. Low population densities made profitable commerce difficult. The massive barrier of the Congo rainforests was as imposing as the Sahara blocking trade through the center of the continent.

It was the arrival of the Islamic armies that transformed the economies of much of Africa. Islam had comparatively little impact on North Africa where large cities, literacy, and centralized states had been the norm. The Arabs were far more effective a penetrating the Sahara than the Christians ever were, largely due to the camel, which had carried the Arab expansion and would soon carry large amounts of trade across the desert.

Thus a series of states developed in the Sahel on the southern edge of the Sahara that made immense profits from trading across the desert. The first of these was the Kingdom of Ghana, reaching it peak in the twelfth century. Soon others such as the Mali Empire and Kanem-Bornu also arose in this region. The main trade of these states was gold that was plentiful in Guinea. Also important was the trans-Saharan slave trade that shipped large numbers of slaves to North Africa.

An equally important trade was developing on the east coast of the continent as Swahili traders linked the region into an Indian Ocean trading network that brought imports of Chinese pottery and Indian fabrics in exchange for gold, ivory, and slaves.

European influence
The Atlantic Ocean had long been all but impenetrable to the galleys that plied the Mediterranean. That any ship needed to pass thousands of kilometers of waterless desert before reaching any populated regions also made trade impossible. These barriers were overcome by the development of the caravel in Europe. Previously trade with Sub-Saharan Africa could only be conducted through North African middlemen. Now Europeans could trade directly with the Africans themselves.

The first to arrive were the Portuguese who began significant trading with West Africa in the fifteenth century. This trade was primarily for the same commodities the Arabs had bough, gold ivory and slaves. The Portuguese sold the Africans Indian cloth and European manufactured goods, but refused to sell them guns. Soon, however, other European powers such as France, Denmark, the Netherlands and Britain were developing their own trade with Africa, and they had fewer worries.

This valuable trade led to rapid change in West Africa. The region had long been agriculturally productive and, especially in western Nigeria densely populated. The massive profits from trade and the arrival of guns lead to significant centralization and a number of states formed in the region such as the Ashanti Confederacy and Kingdom of Benin. These states became some of the wealthiest and most advanced in Africa. The wealthy merchants began to send their children to European universities and their well armed standing armies could challenge European forces.

The most important trade fueling this economic growth in West Africa was that of slavery. Early historians believed slavery had a strongly negative impact on the region, depriving it of population and fueling warfare. Modern historians believe the African slave trade had a far smaller effect on Africa that was earlier believed. While the Atlantic slave trade had a massive demographic effect on the Americas, the number of slaves exported annually was more than made up for by natural population growth. While those sold into slavery were condemned to repression, servitude and an early death, to those left behind the trade was quite profitable and beneficial. Slaves were not cheap, and annually hundreds of thousands of muskets arrived in West Africa, vast quantifies of clothing and other manufactured goods. All evidence points to standard of living for West Africans increasing steadily during this period.

Colonialism
Under colonial rule, Africa was mainly utilized by European powers for the purpose of growing cash crops such as cotton in West Africa and rubber in the Congo. The plantation system of farming was introduced in order to grow large quantities of these commodities employing cheap (often slave) native labor for export to the mother country without compensation. Mining for gems and precious metals such as gold was developed in a similar way by wealthy European entrepreneurs such as Cecil Rhodes.

Today, many African economies suffer from the legacy of colonialism. The utilitarian attitude of European countries toward their colonial possesions stopped them from building adequate infrastructure in Africa. In agriculture, the plantation systems that they introduced are highly unsustainable and cause severe environmental degradation. For example, cotton severely lowers soil fertility wherever it is grown, and areas of West Africa that are dominated by cotton plantations are now unable to switch to more profitable crops or even to produce food because or the depleted soil. Recently, more countries have initiated programs to revert to traditional, sustainable forms of agriculture such as shifting cultivation and bush fallow in order to grow enough food to support the population while maintaining soil fertility to allow agriculture to continue in future generations. (Gyasi)