Thomas Clarkson was the only abolitionist to dedicate his life to the cause and his conviction remained unchanged. He was more than willing to 'go the extra mile'. As well as the thoroughness of his research, he brought many of his own special talents to the movement.
Before Clarkson joined the campaign, it had generated only limited interest amongst the public. Within a few years, Clarkson had turned abolition into the most prominent political issue of the day. He accomplished this through sheer determination and a new and highly creative approach to publicity.
He understood economics and the impact of the Slave Trade on the economy and how hard it would be to oppose those with a vested interest in the trade. Achieving abolition, he realized, would require hard evidence and mass public pressure, as well as the support of influential people and sympathizers, such as the young politician, William Wilberforce.
To engage with the public, Clarkson travelled on horseback from city to city. He met with officials and gave public talks. He used the manacles, leg-irons and thumbscrews he bought in Liverpool, as well as the contents of his African box, to demonstrate the evils of slavery and the opportunities for an alternative trade. His research provided the information that allowed Wilberforce to construct the speeches, that made such an impact in Parliament.
Clarkson was very good at providing a balanced view, based on evidence, that appealed to different influential groups. He realized, for example, that the the high level of deaths amongst British seamen (about 20 per cent on each voyage) would provide a much stronger argument with the Establishment, as it showed that the trade was uneconomic as well as immoral.
Clarkson also understood the value of propaganda and encouraged the publication of the 'Brookes' diagram (showing Africans closely packed into a ship), which proved such an effective image. He also encouraged women, who could not vote, to show their support for the cause, by wearing brooches and bracelets with the campaign logo, which were handed out at public meetings. Unlike Wilberforce, Clarkson was also in support of the Sugar Boycott, organized after the defeat of the 1771 act in Parliament.
He was also an excellent author, condensing and editing the large volume of evidence produced, into a more concise and readable version. In 1787, when he published his pamphlet, 'A Summary View of the Slave Trade and of the Probable Consequences of Its Abolition', Jane Austin, who completely disagreed with his views on slavery, was so impressed with Clarkson's writing style, that she claimed, after reading one of his books, that she was "in love with its author".