Between 1620 and 1820, twelve millions of Africans were transported across the Atlantic.
At the time theBritish were the biggest slave traders and their trade was known as the triangular trade, because of the route it took.
Ships sailed from Britain full of goods such as guns and cloth. These goods were exchanged with African chiefs for slaves, then they carried their cargo across the Atlantic to the Americas and the Caribbean Islands. Here the traders sold the slaves at public actions to raise money, and with that money they bought sugar, tobacco and molasses. After that, the ships returned to Britain carrying this cargo, which was sold at huge profits. During the Industrial Revolution the profits of the slave trade was the 5% of the whole British economy. After they arrived in America, families were often divided up and small children were taken from their mothers. Slaves belonged to their owners and had no legal rights, they couldn't meet other slaves in public, they couldn't travel without permission and it was also illegal to teach them how to read or write; slaves who disobeyed could be beaten.
But in 1808 the American Congress outlawed the system of slavery, even though it continued for more than fifty years. Another important thing was The Emancipation Proclamation issued by President Lincoln in 1863, which freed the slaves held in the southern states of U.S.A. Two years later the U.S Constitution prohibited, by the 13th Amendment, slavery in the whole country.