Britain dominated the slave trade for over 100 years. Only when the British public turned against slavery did Britain try to end, or abolish, it in Europe and the Americas.
During the 1700s and 1800s, the British public supported the institution of slavery. British slave traders shipped huge numbers of Africans to English, French and Spanish colonies in the Americas. They made enormous profits, and much of this wealth later helped finance the Industrial Revolution.
Some people in Britain began protesting slavery in the late 1700s. Lord Mansfield declared, "The air of England has long been too pure for a slave, and every man is free who breathes it." Many still defended slavery, saying that abolition would ruin the British economy. Efforts to abolish slavery failed in Parliament until abolitionists exposed the horrors of the slave trade. These reports fueled public distaste for the institution.
Slavery within England was outlawed in 1772. In 1807, the Abolition Act ended the British slave trade. And in 1833, the Emancipation Act abolished slavery in all British colonies.