William WilberforceBy the late 18th century, over eleven million African men, women and children had been taken from Africa to be used as slaves in the West Indies and the American colonies. Great Britain was the mightiest superpower on earth and its empire was built on the backs of slaves.  The slave trade was considered acceptable by all but a few.  Of these, even fewer were brave enough to speak against it.  William Wilberforce was one such man.

William Wilberforce (24 August 1759 – 29 July 1833) was a British politician, a philanthropist and a leader of the movement to abolish the slave trade. A native of Kingston upon Hull, Yorkshire, he began his political career in 1780 and became the independent Member of Parliament for Yorkshire (1784–1812). In 1785, he underwent a conversion experience and became an evangelical Christian, resulting in major changes to his lifestyle and a lifelong concern for reform. In 1787, he came into contact with Thomas Clarkson and a group of anti-slave-trade activists, including Granville Sharp, Hannah More and Charles Middleton. They persuaded Wilberforce to take on the cause of abolition, and he soon became one of the leading English abolitionists. He headed the parliamentary campaign against the British slave trade for twenty-six years until the passage of the Slave Trade Act 1807.

As a direct result of the passage of that Act, between 1808 and 1860 the British Navy seized approximately 1,600 slave ships and freed 150,000 Africans who were aboard. Action was also taken against African leaders who refused to agree to British treaties to outlaw the trade, for example against "the usurping King of Lagos", deposed in 1851. Anti-slavery treaties were signed with over 50 African rulers.

The Committee for the Abolition of the Slave Trade which led the campaign that pushed the act through, was formed in 1787 by a group of Evangelical English Protestants allied with Quakers to unite in their shared opposition to slavery and the slave trade. The Quakers had long viewed slavery as immoral, a blight upon humanity. By 1807 the abolitionist groups had a very sizable faction of like-minded members in the British Parliament. At their height they controlled 35–40 seats. These parliamentarians saw their personal battle against slavery as a divinely ordained crusade and were extremely dedicated.

Wilberforce was convinced of the importance of religion, morality, and education. Beyond his pivotal role in the abolition of slavry, he championed causes and campaigns such as the Society for Suppression of Vice, British missionary work in India, the creation of a free colony in Sierra Leone, the foundation of the Church Mission Society and the Society for the Prevention of Cruelty to Animals.

In later years, Wilberforce supported the campaign for the complete abolition of slavery, and continued his involvement after 1826 when he resigned from Parliament because of his failing health. That campaign led to the Slavery Abolition Act 1833, which abolished slavery in most of the British Empire and remained in force until 1998. Wilberforce died just three days after hearing that the passage of the Act through Parliament was assured.

The abolition of slavery was a monumental change in social policy and had massive economic consequences throughout the British Empire.  As an indication of the magnitude of that achievement, the Act included the provision of some twenty million pounds Sterling as compensation to slave-owners who would be forfeiting their property. At the time, this amount was 40% of the government's total annual expenditure. In all, the government paid out over 40,000 separate awards indicating that slavery did not just naturally expire; it was ended.