After 1700, the numbers of slaves being transported increased greatly. Perhaps 8.5 million Africans were taken as slaves to the Americas.
A British slave ship set off from Liverpool, Glasgow or Bristol, carrying trade goods and sailed to West Africa.
Some slaves were captured directly by the British traders. They ambushed and captured local people in Africa.
Most slave ships got their slaves from British 'factors', who lived full-time in Africa and bought slaves from local tribal chiefs. The chiefs would raid a rival village and sell their captured enemies as slaves.
In 1700, a slave cost about £3-worth of traded goods, eg cloth, guns, gunpowder and brandy.
The slaves were marched to the coast in chained lines called coffles, where they were held in prisons called 'factories'.
The slave ship then sailed across the Atlantic to the West Indies – this leg of the voyage was called the 'Middle Passage'.
In the West Indies the slaves were sold at an auction called a 'scramble'. Some were sent to 'seasoning camps' to be trained to obey, often using brutal methods.
The selling price of a slave in the West Indies in 1700 was £20, so there was a good profit to be had, which made the risks of long journeys and possible harsh weather worthwhile.
Some ships, but not all, then loaded up with sugar and rum to sell in Britain, before making the voyage back home.