Early life
Thomas Clarkson was born on 28th March 1760 at Wisbech Grammar School, then situated on Ship Lane, now Hill Street, pictured below:

Wisbech Grammar School where Thomas was born and educated. [From the Wisbech Album: a collection of photographs of Wisbech & the surrounding area c.1870-1890 Cambridgeshire Collection C.66.2]

His father, the Rev. John Clarkson, was headmaster and curate of All Saints, Walsoken. Thomas was the eldest of three children – he had a sister, Anne, and a brother, John.
Their mother, Anne (1735- 1799) was related to the Banyers of Wisbech and after her husband’s death the family moved to York Row.

No. 8 York Row, Wisbech a house owned by one of Anne Clarkson's cousins. Thomas lived here and continued to attend the Grammar School until he was fifteen when he moved to St. Paul’s School in London and then to St. John’s College, Cambridge.

 
The essay that starts it all
In 1785 while studying at Cambridge, Thomas Clarkson won first prize in a Latin essay competition, ‘Is it right to make slaves of others against their will?”

During the course of his research he discovered the abhorrent truth about slavery and the slave trade. Unable to dismiss his findings from his mind he knew that something must be done to “see these calamities to their end”. He determined to publish an English translation of his essay and see how it was received by the public.

“An Essay on the Slavery and Commerce of the Human Species, Particularly the African” by Clarkson published by James Phillips, a Quaker bookseller.

It was immediately popular and made many converts to the cause. Phillips, introduced him to others who were already engaged in the fight against slavery, including Granville Sharp and a small group of Quakers.

At this point Clarkson also met William Wilberforce for the first time. Already sympathetic to anti-slavery, Clarkson recruited him to the campaign. As early as spring 1787 Wilberforce promised to lay the question of abolition before the House of Commons.

Collecting Evidence
Clarkson decided a national organisation was needed to build up public support for abolition and on May 22nd 1787 twelve men (Clarkson, Granville Sharp and members of the old Quaker committee) formed the Committee for Effecting the Abolition of the Slave Trade.

Clarkson was asked to undertake fact-finding journeys on how the slave trade was conducted and to uncover proof of the cruelty and injustices. Over the next seven years (1787–1794) he travelled the length and breadth of the country on horseback, covering an astonishing 35,000 miles.
In the major slave trading ports such as Bristol and Liverpool the idea of abolition was deeply unpopular and at least one attack was made on Clarkson’s life.

“Iron instruments used in this cruel traffic” bought in a Liverpool shop by Clarkson during one of his visits to the port. The details appeared in Clarkson’s History of the Abolition of the African Slave Trade A – handcuffs B – leg shackles C /D/E – thumb screw G/F/H – speculum oris (for force feeding)

In 1804, a Bill to abolish the Slave Trade was introduced into the Commons but was lost by just 7 votes the following year. Spurred into action by this disappointment, Clarkson set off on another tour of the country to obtain new evidence, revive old enthusiasm and gather new supporters. He also published another pamphlet.

1807
In January 1807 a new Prime Minister, Lord Grenville, one of the original abolitionists, decided that it was time to try again. The bill was introduced in the Lords where most of the previous opposition had been. It was passed by a large majority in both Houses and after another final vote in the Lords, Royal assent was given on 25th March 1807.
“Thus ended one of the most glorious contests, after a continuance of twenty years, of any ever carried on in any age or country.” (Clarkson)

The fight goes on.
Following the abolition of the slave trade in 1807 Clarkson and the others on the Committee worked hard to make sure that the act was enforced. They also began a new campaign focusing on the abolition of slavery itself. He travelled widely again – both at home and abroad where he acted as an unofficial ambassador for the abolitionist cause, and he continued to write campaign literature.

In 1833 the Act abolishing slavery in the British Empire was finally passed. Much of Clarkson’s work was now directed across the Atlantic where the campaign against slavery was only just beginning.

Final years

Clarkson's address to the Anti-Slavery Convention in London in June 1840 at the age of 80 was his last public appearance. He died at Playford in Suffolk on 26th September 1846, aged 87, and is buried in the parish churchyard.

Tributes
In 1833 the inhabitants of Wisbech asked Clarkson to sit for his portrait and the painting still hangs in the Council Chamber of Wisbech Town Hall.

In 1996, to mark the 150th anniversary
of Clarkson’s death, a memorial was
unveiled in Westminster Abbey close to the tomb of his friend and collaborator William Wilberforce. It simply reads 'Friend to slaves'.