Lesson 1.7 · Unit 1 · CED topic 1.9
The Atlantic slave trade
The transatlantic slave trade was one of the largest forced migrations in history and a central part of European colonial expansion. Learning Objective L asks you to explain the causes for and the development of the slave trade. The CED's explanation is specific: Europeans expanded the trade of enslaved Africans in response to the establishment of a plantation economy in the Americas and demographic catastrophes among indigenous peoples. This lesson places the trade in that economic setting, describes how it worked, and examines how people at the time understood it.
Learning objective.
- 1L. Explain the causes for and the development of the slave trade.
Historical developments.
- 1.3.IV.C. Europeans expanded the trade of enslaved Africans in response to the establishment of a plantation economy in the Americas and demographic catastrophes among indigenous peoples.
Origins and causes
Slavery existed in many societies, including Africa, the Mediterranean, and the Islamic world. What changed after 1500 was the scale and the system.
- Sugar and plantations. Europeans learned to grow sugar on Atlantic islands such as Madeira and the Canaries, and then in Brazil and the Caribbean. Sugar, and later tobacco, cotton, and rice, was grown on large estates called plantations that needed many workers for hard, year-round labor.
- The labor shortage. European diseases and forced labor killed large numbers of indigenous people in the Americas. The Spanish encomienda system had forced native peoples to work, but that supply collapsed. Europeans did not wish to settle in tropical colonies as laborers, and indentured servants from Europe were never enough.
- Existing slave trades. Portuguese traders had bought enslaved people on the African coast since the 1440s. The Europeans took advantage of existing African trading states, which sold captives, usually taken in war or raids, in exchange for goods such as cloth, metalware, firearms, and alcohol.
- Racial ideas. Europeans increasingly justified slavery by claiming Africans were inferior. Over time, laws tied slavery to race and made it hereditary.
How the trade developed
The Portuguese were the first major carriers in the sixteenth century, sending captives to Brazil and to Spanish colonies under licenses called asientos. In the seventeenth century the Dutch, English, and French entered the trade and settled sugar islands such as Barbados and Saint-Domingue. The eighteenth century was the peak: British ships carried the largest share, and Liverpool, Bristol, Nantes, and Lisbon grew rich as slave-trading ports. All told, historians estimate that roughly twelve million Africans were embarked on ships across the Atlantic, and that many died on the way or soon after landing.
- The Middle Passage. Captives were packed into ships for the ocean crossing, which lasted weeks or months. Disease, brutal conditions, suicide, and revolts killed a significant number on each voyage.
- Planter society. In the Americas, planters held enormous power, and enslaved people were treated as property, forced to work under violence, and often separated from their families. Societies in the Caribbean and Brazil were majority-enslaved, and white elites feared revolt.
The trade tied together three continents in what is often drawn as a triangle: manufactured goods from Europe to Africa, enslaved people from Africa to the Americas, and sugar, tobacco, and other products from the Americas to Europe. In reality there were many routes, and the pattern was more complicated than a neat triangle.
Effects and resistance
For Europe, the trade enriched merchants, shipbuilders, banks, and port cities and supplied raw materials and consumer goods, such as sugar, that shaped European diets. For Africa, the loss of millions of people, the spread of warfare to capture captives, and the strengthening of some states that sold slaves had lasting effects. Enslaved people resisted in many ways, from daily sabotage to open revolt and the formation of communities of escaped people.
Description of: The Interesting Narrative of the Life of Olaudah Equiano (1789), the autobiography of a man who said he was born in what is now Nigeria, was kidnapped as a child, endured the Middle Passage, and later purchased his freedom and became an abolitionist in Britain. In the passage on the voyage, Equiano describes the stench, the crowding, the sickness, and his terror on the ship.
Sourcing (HIPP). The narrative was written by a man who had experienced slavery, so the point of view is first-hand, and it is one of the rare accounts by an enslaved African. It was written and published in 1789 in Britain, in the abolition campaign, so its purpose was to persuade British readers to end the trade and the audience was a literate, mostly white readership. Historians have discussed whether Equiano described his early life from memory or drew on others' accounts, so the narrative is strongest as evidence of the experience of the passage and of abolitionist argument.
Claim. Equiano's account shows the human cost of the Middle Passage and was used to argue for abolition.
Evidence. In the described passage, he reports crowding, stench, and sickness aboard the ship, and his fear.
Reasoning. The detail supports the CED's point that the trade was a large and brutal system, and the 1789 publication date and British audience show how the account was used in the abolition movement. A limit is that it comes from one individual and was shaped for readers, so it cannot show how every voyage went.
Question. Explain one cause of the expansion of the Atlantic slave trade.
Model. One cause was the growth of plantation agriculture in the Americas. Sugar and tobacco estates needed large numbers of laborers, and the supply of indigenous workers had collapsed because of disease and forced labor. European planters and merchants turned to enslaved Africans, bought through African trading partners, to fill the demand.
The CED names two causes: the plantation economy and the demographic catastrophe among indigenous peoples. A top-level answer links them: disease destroyed one labor supply, plantations created demand for another. Remember the other direction too, that the trade shaped the European economy through ports, banks, and consumer goods. Avoid describing enslaved people as passive; resistance is part of the history, as are African participants in the trade.
- What crops drove the demand for enslaved labor in the Americas?
Show answer
Sugar above all, and also tobacco, rice, and later cotton, grown on large plantations.
- Explain how the decline of indigenous populations contributed to the slave trade.
Show answer
Disease and forced labor killed many indigenous workers, creating a labor shortage that European colonists filled by importing enslaved Africans.
- What was the Middle Passage?
Show answer
The Atlantic crossing that carried enslaved Africans to the Americas, marked by crowding, disease, and high death rates.
- Which European powers carried the largest share of the trade, and when did it peak?
Show answer
Portugal carried the most over the whole period, with Britain a leading carrier in the eighteenth century, when the trade reached its peak.
- Name one way enslaved people resisted.
Show answer
Revolt, escape and the formation of communities of escaped people, or everyday acts such as slowing work and sabotage.
- Why is Equiano's narrative useful, and what limit should a historian keep in mind?
Show answer
It is a rare first-hand account by someone who experienced the Middle Passage and shows how abolitionists used personal testimony. It reflects one person's story and was shaped for a British audience, so it does not represent every experience.