PortCities London

London and the transatlantic slave trade

The horror of the slave trade

Stage 1: Trade with Africa

Scenes on the coast of Africa
View full size imageScenes on the coast of Africa. © NMM
In its most basic form, the transatlantic trade in enslaved people was a commercial triangle connecting Europe, West Africa and the Americas. Ships left British ports such as London carrying trade goods for West Africa. These might include cotton cloth, guns, gunpowder and ammunition, ironware, alcohol, trinkets, etc.

The ship’s captain then spent many weeks off the African coast trading goods for Africans captured by African slave traders. The process of negotiating the exchange of goods for Africans was very time-consuming. But once the ship was full with many hundreds of Africans and restocked with water and supplies, the captain set sail across the Atlantic.

Stage 2: The 'middle passage'

Slave ship
View full size imageSlave ship. © NMM
The Africans crowded below the deck of the slave ship came from across a huge area of the continent. Some would have been on board the ship for weeks or even months before beginning the terrible 'middle passage' to the Americas.

The conditions on board the ship were unimaginably awful. The human cargo was packed together as tightly as possible. There was no sanitation, poor ventilation, little opportunity for exercise and only meagre rations of food and water.

Slaves below deck
View full size imageSlaves below deck. © NMM
Death caused by disease and despair was common.  Infectious diseases such as smallpox spread quickly in the foul atmosphere and filthy surroundings of the hold, killing hundreds.

Bad weather might prolong the crossing, leading to a shortage of food and water. Sometimes, slave ship captains threw Africans overboard to save provisions. The Africans were insured like cattle and the captain could expect compensation for such 'losses'.

It has been estimated that more than 450,000 Africans died on British ships during the horrific 'middle passage'.

The crews of slave ships were always afraid of a revolt and discipline was therefore very harsh. Very few shipboard slave revolts were successful. Even if the Africans did manage to seize control of the ship, they lacked the skills necessary to navigate and steer the vessel safely to shore.

Stage 3: Sold into slavery

Separation of families
View full size imageSeparation of families. © NMM
Once in the Americas, the surviving Africans were sold into slavery at auction. They were employed on plantations, in domestic service, in mines and in industry. Families and friends were traumatically separated in Africa, on the ship and at the auction.

Conditions on the plantations were very harsh. The enslaved Africans were forced to work very long hours, especially at harvest time when working was almost non-stop. Slaves were subjected to severe discipline and acts of cruelty and indecency.

Planting the sugar cane
View full size imagePlanting the sugar cane. © NMM
The average life expectancy for an enslaved person in the British West Indies was only seven years. In North America, some planters estimated that slaves could be worked to death after only four years. By that time they reckoned they had made a return on their initial investment.

Shipping sugar (Antigua)
View full size imageShipping sugar (Antigua). © NMM

For the ship’s captain, the most important transaction was securing the cargo of sugar, coffee, tobacco or cotton. It was this that would gain the largest profit in Britain and finance the next voyage. 

At each stage of this triangular trade, the main motivation for those involved – whether British captain, African slave trader, or Caribbean plantation owner – was profit.

This inhuman and unbelievably cruel system of trade and production continued to grow throughout the 18th century as the demand for plantation goods expanded.


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