Richardson, David. "Cultures of Exchange: Atlantic Africa in the Era of the Slave Trade". Transactions of the Royal Historical Society, Vol.19 (2009): 151-179.

Richardson, David. "Cultures of Exchange: Atlantic Africa in the Era of the Slave Trade". Transactions of the Royal Historical Society, Vol.19 (2009): 151-179.

• The growth in transatlantic trade in the 1600s was driven by a rapid decline in the costs of transporting goods across the ocean, mainly due to increases in the maritime security of the region through reduction of piracy. This same conditions allowed a commercial revitalization of the Mediterranean Sea in the 1200s (153).
• Christians had, by the 1500s, developed a stigma or prohibition against the enslavement of fellow Christian peoples, this served as the primary reason why Africans rather than Europeans -- mostly likely Germans and Slavs -- were enslaved for plantation work in the Americas. Muslims also targeted non-Muslims for slave trading (153).
• Although African slavers are often described as the weaker of the two commercial parties in modern histories, the continued use of uneven exchange -- in which Africans sometimes had the advantage -- rather than raiding demonstrates the strength of African polities versus Europeans (156).
• Merchant communities in ports were usually responsible for the conduct of the slave trade, working as middlemen between European buyers and active slavers in inland Africa. Inland kingdoms sometimes became jealous of the wealth of the slave merchants, resulting it the conquest of the coastal states (158).
• The first slaving was small scale and began in Senegambia, near Bissau, and south of the Congo. By its height, when hundreds of times more slaves were being purchased, the Gold Coast, Bight of Biafra, and Bight of Benin were the most popular destinations. Almost 4/5 of all slaves were purchased from the Congo, Bight of Biafra, Gold Coast, or the Bight of Benin (159).
• This trade was divided geographically between different states. For example, Portuguese slavers dominated the slave trade South of the Congo through strong connections in Angola and Brazil (159-160), whereas the Nederlandish focused on the Gold Coast, the French on Senegal, the Bight of Benin, and Gabon, and the English were further divided with different cities monopolizing trade in different areas (160).
• Within these slaving zones, and despite large numbers of maritime communities, a few ports dominated the export of slaves in each region. 2/3 of all slaves came from only 10 Atlantic ports, all of which were on the Gulf of Guinea (162).
• The success of the slave trade depended on the ability of Africans and Europeans to come to agreement on terms of exchange and methods for resolving disputes, as well as securing rights to property. The presence of violence in Upper Guinea compared to other areas demonstrates that the success of these mechanisms varied along the coast (164-165).
• The ability of slavers to guarantee the safety and success of slaving was a key point of competition between coastal port cities, as the port of Old Calabar specifically sought to reassure traders that they would be safe after the murder of two Liverpool merchants in 1780, fearing a decline in business from Liverpool (165).
• Political organization in coastal African often depended on the success of the slave trade and most political structures were built around harvesting rents from control over the trade through taxes, tariffs, and rights of acquisition (165).
• The functioning of the successful slave trade depended on political order in coastal Africa and the development of social capital that allowed for the successful transport of slaves from the interior through different polities to coastal areas by different groups all expected payment. When political order broke down, so did the slave trade (166).
• There have been numerous claims that European merchants 'duped' Africans into exchanging slaves for worthless baubles, but there is little evidence of this. Africans always had control over what goods they wanted from Europeans, including the types of firearms (166). The goods exchanged for slaves altered with African tastes, requiring Europeans to produce or acquire new types of goods and shaping the Atlantic and European export economies (167).
• Although barter was common, the slave trade came to be mainly done in coastal African currencies by the 1800s, with Europeans purchasing slaves in hard currency gained from the export of goods an earlier date (167).
• Slaves were used in the production of many crops in the Americas, but none more so than sugar. It is estimated that perhaps 4/5 of all slaves ever taken to the Americas were involved in the production and processing of sugar cane (168).
• Expanded demand for slaves in the Americas in the 18th Century, largely driven by the expansion of sugar production to the Caribbean and inland parts of Brazil, caused Africans to raise the prices for slaves throughout this period (169). There are some signs suggesting that traditional African suppliers had a 'slave shortage' in the 1750s, driving European merchants to pay more, wait longer for slaves to be delivered, and trade with previously marginal suppliers (170).
• The pressure placed on African slavers increased in the latter half of the 18th Century, resulting in the development of new systems of credit to increase efficiency by reducing the time ships spend waiting for slaves. The increased demanded also extended commercial networks deeper into the interior (170).
• American preferences for different kinds of slaves developed over time, beginning with an obvious preference for 'prime specimens' of adult men aged 15 to 30 and of considerable height, and expanding to distinct ethnic preferences over time, such as a prejudice against Igbo slaves (171-172).
• Very little value was placed on maintaining gender balances between slaves, who were seen as an expendable and renewable resource rather than a potential breeding population of livestock. As a result women were used in the same mining and sugar processing work as men without regards to reproduction, separate from men only because they were weaker and thus less valued (172).
• These systems of valuation represented a significant diversion from the prices used in the older trans-Saharan slave trade, where pre-pubescent girls and eunuchs commanded by far the highest prices. They were valued for their ability to be easily incorporated into the wealthy household that bought them (174-175).
• Prior to the entry of European merchants into the slave market, slaving raids to acquire women and children also produced large number of adult men who were unprofitable on trans-Saharan and domestic markets and presented a greater danger to slavers. These men were often slaughtered to prevent insurrection, but the transatlantic slave trade present an ideal way to turn this 'liability' into a profit (175-176).
• "Harvest seasons in Africa commonly determined the timing of voyages as captives needed to be fed" (177-178).