Henry Thornton, the youngest son of John Thornton (1720–1790) and Lucy Watson (1722–1785), was born in Clapham, on 10th March 1760. His father was a highly successful merchant. After a brief education he joined the family business. In 1780 he became a partner but in 1784 he joined the banking firm of Down and Free which soon became Down, Thornton, and Free. According to his biographer, Christopher Tolley: "Under his management, and with the help of a legacy of about £40,000 inherited from his father, Thornton's bank grew from a smallish concern into one of the largest in London, with an extensive network of country connections."
In September 1782, he was elected to the House of Commons for the seat of Southwark. He held progressive political opinions and was in favour of parliamentary reform and the abolition of the slave trade. Thornton was a poor orator and spoke infrequently in parliament. Thornton was very close to his cousin, William Wilberforce, and like him was converted to Evangelical Christianity. Thornton joined the Clapham Set, a group of evangelical members of the Anglican Church, centered around Henry Venn, rector of Clapham Church in London. As a result of this conversion, Thornton became interested in the subject of social reform. Other members included Wilberforce, Hannah More, Granville Sharp, Zachary Macaulay, James Stephen, Edward James Eliot, Thomas Gisbourne, John Shore and Charles Grant.
In 1787 Thomas Clarkson, William Dillwyn and Granville Sharp formed the Society for the Abolition of the Slave Trade. Although Sharp and Clarkson were both Anglicans, nine out of the twelve members on the committee, were Quakers. This included John Barton (1755-1789); George Harrison (1747-1827); Samuel Hoare Jr. (1751-1825); Joseph Hooper (1732-1789); John Lloyd (1750-1811); Joseph Woods (1738-1812); James Phillips (1745-1799) and Richard Phillips (1756-1836). Influential figures such as Thornton, Charles Fox, John Wesley, Josiah Wedgwood, James Ramsay, and William Smith gave their support to the campaign. Clarkson was appointed secretary, Sharp as chairman and Hoare as treasurer.
Thornton played a leading role in opposition to slavery in the House of Commons. In 1787 Granville Sharp came up with the idea that the black community in London should be allowed to to start a colony in Sierra Leone. The country was chosen largely on the strength of evidence from the explorer, Mungo Park and a encouraging report from the botanist, Henry Smeathman, who had recently spent three years in the area. The British government supported Sharp's plan and agreed to give £12 per African towards the cost of transport. Sharp contributed more than £1,700 to the venture. Several supporters of the Society for the Abolition of the Slave Trade invested money into what became known as the Province of Freedom. Sierra Leone Company. This included Henry Thornton, William Wilberforce, Thomas Clarkson, Samuel Whitbread and William Smith.
Richard S. Reddie, the author of Abolition! The Struggle to Abolish Slavery in the British Colonies (2007) has argued: "Some detractors have since denounced the Sierra Leone project as repatriation by another name. It has been seen as a high-minded yet hypocritical way of ridding the country of its rising black population... Some in Britain wanted Africans to leave because they feared they were corrupting the virtues of the country's white women, while others were tired of seeing them reduced to begging on London streets."
Granville Sharp was able to persuade a small group of London's poor to travel to Sierra Leone. As Hugh Thomas, the author of The Slave Trade (1997), has pointed out: "A ship was charted, the sloop-of-war Nautilus was commissioned as a convoy, and on 8th April the first 290 free black men and 41 black women, with 70 white women, including 60 prostitutes from London, left for Sierra Leone under the command of Captain Thomas Boulden Thompson of the Royal Navy". When they arrived they purchased a stretch of land between the rivers Sherbo and Sierra Leone.
Soon after arriving the colony suffered from an outbreak of malaria. In the first four months alone, 122 died. One of the white settlers wrote to Sharp: "I am very sorry indeed, to inform you, dear Sir, that... I do not think there will be one of us left at the end of a twelfth month... There is not a thing, which is put into the ground, will grow more than a foot out of it... What is more surprising, the natives die very fast; it is quite a plague seems to reign here among us."
Adam Hochschild has pointed out: "As supplies at Granville Town dwindled and crops failed, the increasingly frustrated settlers turned to the long-time mainstay of the local economy, the slave trade.... Three white doctors from Granville Town ended up at the thriving slave depot... at Bance Island." Granville Sharp was furious when he discovered what was happening and wrote to the settlers: "I could not have conceived that men who were well aware of the wickedness of slave dealing, and had themselves been suffers (or at least many of them) under the galling yoke of bondage to slave-holders... should become so basely depraved as to yield themselves instruments to promote, and extend, the same detestable oppression over their brethren."
Sharp refused to accept the negative reports coming from Sierra Leone. He wrote that he had chosen "the most eligible spot for... settlement on the whole coast of Africa". With the financial support of William Wilberforce, Thomas Clarkson and Samuel Whitbread, Sharp dispatched another shipload of black and white settlers and supplies. It was not long before Sharp began receiving reports that many of the new settlers were "wicked enough to go into the service of the slave trade".
In 1789, a Royal Navy warship making its down the coast fired a shot that set a Sierra Leone village on fire. The local chief took revenge by giving the settlers three days to depart, and then burning Granville Town to the ground. The remaining settlers were rescued by the slave traders on Bance Island. Sharp was devastated when he discovered that the last of the men he had sent to Africa were now also involved in the slave trade.
In 1791 the Sierra Leone Company took over from Granville Sharp's failed Province of Freedom. Thornton became the chairman and one of his first actions was to sack Alexander Falconbridge, who had been a disaster as the company's commercial agent. John Clarkson was now sent to Halifax, Nova Scotia, where there was a community of former American slaves who had fought for the British in the War of Independence, to recruit settlers for the abolitionist colony. With the support of Thomas Peters, the black loyalist leader, he led a fleet of fifteen vessels, carrying 1196 settlers, to Sierra Leone, which they reached on 6th March, 1792. Although sixty-five of the Nova Scotians died during the voyage, they continued to support Clarkson who they called "their Moses".
John Clarkson became governor of the colony that was appropriately named as Freetown. However, as Hugh Brogan has argued: "It was the understanding between Clarkson and the Nova Scotians that got the colony through its very difficult first year. Clarkson's services were at first generally recognized. But great strains arose between him and the company directors, partly religious (he was not sympathetic to the insistent evangelicalism of Henry Thornton, the company chairman), partly because of the usual tension between head office and the man on the spot, and above all because Clarkson insisted on putting the views and interests of the Nova Scotians first, whereas the directors wanted the enterprise to show an early profit, so that they could compete successfully with the slave traders and bring to Africa Christianity."
In 1792 Thornton bought Battersea Rise, a villa on Clapham Common which he shared with William Wilberforce. The library of the house became a meeting-place for the Clapham Set. On 1st March 1796 Thornton married Marianne Sykes (1765–1815), only daughter of Joseph Sykes, a merchant from Kingston upon Hull and an evangelical. They had nine children. His biographer has argued that: "The marriage was affectionate; in his family Thornton was warmer and more spontaneous than he usually appeared to the outside world. He took great care over the education and religious upbringing of his children, insisting on their being useful and aware of public affairs from an early age."
Down, Thornton, and Free became one of the most important banks in London. Thornton also used his business skills to run the Sierra Leone Company. His biographer, Christopher Tolley, has pointed out: "The company aimed to confer on Africa the blessings of European religion and civilization through a trading operation that would be both profitable and free from the taint of slavery. Thornton was the company's most influential director and remained chairman throughout its life, writing virtually all its published reports and administering Sierra Leone from offices alongside his bank in Birchin Lane."
A close friend of Hannah More, Thornton contributed to her series of pamphlets, Cheap Repository Tracts, (1795-1798) on political issues for the lower classes. It has been claimed that within a year these pamphlets sold over 2 million copies. They were mainly bought by the wealthy to distribute to the poor. The success of these publications paved the way for the establishment of the Religious Tract Society. It has been argued by James Stephen that he "gave away between £2,000 and £9,000 a year, six-sevenths of his income before his marriage and one-third after it."
In 1802 Thornton published An Enquiry into the Nature and Effects of the Paper Credit of Great Britain. The book provided a complete account of the English monetary system. This included a detailed discussion of how the Bank of England should act to prevent instability. John Stuart Mill described the book as "the clearest exposition that I am acquainted with, in the English language, of the modes in which credit is given and taken in a mercantile community". It has been claimed that Karl Marx was influenced by Thornton's work.
Thornton joined forces with Zachary Macaulay to launch of The Christian Observer in 1802. He contributed over eighty articles to the journal that supported the philosophy of the Clapham Set. Thornton was also treasurer to the British and Foreign Bible Society and the Church Missionary Society. He also purchased church livings to present to suitable clergymen and was for many years president of the Sunday School Society.
The Abolition of the Slave Trade Act was passed in 1807. Soon afterwards, in July, 1807, members of the Society for the Abolition of Slave Trade established the African Institution, an organization that was committed to watch over the execution of the law, seek a ban on the slave trade by foreign powers and to promote the "civilization and happiness" of Africa. Henry Thornton became treasurer and the Duke of Gloucester took the post of president. Members of the committee included Thomas Clarkson, William Wilberforce, Henry Brougham, James Stephen, Granville Sharp and Zachary Macaulay.
Wayne Ackerson, the author of The African Institution and the Antislavery Movement in Great Britain (2005) has argued: "The African Institution was a pivotal abolitionist and antislavery group in Britain during the early nineteenth century, and its members included royalty, prominent lawyers, Members of Parliament, and noted reformers such as William Wilberforce, Thomas Clarkson, and Zachary Macaulay. Focusing on the spread of Western civilization to Africa, the abolition of the foreign slave trade, and improving the lives of slaves in British colonies, the group's influence extended far into Britain's diplomatic relations in addition to the government's domestic affairs. The African Institution carried the torch for antislavery reform for twenty years and paved the way for later humanitarian efforts in Great Britain."
In 1808 it was decided to transfer the Sierra Leone Company to the crown, the British government accepted Wilberforce's suggestion that Thomas Perronet Thompson would be a suitable governor. He introduced an extensive range of reforms and made serious allegations against the colony's former administrators. Stephen Tomkins, the author of William Wilberforce (2007) has argued: "He (Perronet Thompson) single-handedly abolished apprenticeship and freed the slaves. He filed scandalised reports to the colonial office. Wilberforce told him he was being rash and hasty, and he and his colleagues voted unanimously for his dismissal. Wilberforce advised him to go quietly for the sake of his career."
According to his biographer, Christopher Tolley: "When income tax was introduced he paid more than required, believing that the tax, though just, was not fairly distributed.... He valued a good income, but declined to build up a great fortune for his children, urging the ... to follow his own and his father's example of limited expenses and large liberality."
Henry Thornton became ill in the autumn of 1814 and died of consumption on 16th January 1815 while at the home of William Wilberforce. He was buried in the Thornton vault at the Old Church, Clapham, on 24th January.