The most prominent abolitionists, notably Thomas Clarkson and William Wilberforce, were great publicists. Wilberforce (1759-1833) led the British parliamentary campaign to abolish the slave trade and slavery.
Opinion in Europe was also changing. Moral, religious and humanitarian arguments found more and more support. A vigorous campaign to achieve abolition began in Britain in 1783 and also developed in North America and the Caribbean, often led by the Black churches. In Britain, Thomas Clarkson (1760-1846) was another prominent campaigner who was principally responsible for collecting evidence against the trade. Clarkson was a founder member of the society for effecting the abolition of the slave trade in 1787.
In Liverpool, William Roscoe was one of the best known abolitionists. He wrote poetry and pamphlets in favour of abolition. Opinion in Liverpool was generally pro-slavery and like other abolitionists, Roscoe tended to work behind the scenes rather than openly declaring his views.
An active counter campaign was mounted by those who profited from slavery. The West India lobby of plantation owners and their supporters in the British Parliament fought abolition. Although ultimately unsuccessful, they gained 20 million pounds compensation for plantation owners for the loss of their slaves. Ex-slaves were not compensated.
Despite the abolition of slave trading by Britain and other countries from 1807 onwards, illegal trading continued for a further 60 years. About a quarter of all Africans who were enslaved between 1500 and 1870 were transported across the Atlantic in the years after 1807. Much of this illegal trade was to the sugar plantations of Cuba and Brazil.
From 1815 to 1865, the British Royal Navy undertook antislavery patrols off the West African coast, seizing hundreds of