William Wilberforce's 1789 Speech Against the Slave Trade

William Wilberforce’s speech of 12 May 1789 was his first great address to the House of Commons against the British slave trade. Speaking for about three and a half hours, the young MP for Yorkshire set out the evidence against the trade and proposed twelve resolutions condemning it. The speech made him the parliamentary leader of abolition, yet it also began an eighteen-year struggle before the trade was outlawed.

Background

Wilberforce, born in Hull in 1759, had entered Parliament in 1780. After an evangelical Christian conversion in 1784–85 he looked for a cause, and in 1787 he agreed to lead the campaign against the slave trade in Parliament, encouraged by his friend the Prime Minister William Pitt the Younger.

Outside Parliament the Society for Effecting the Abolition of the Slave Trade, founded in May 1787, was gathering evidence and petitions. Its researcher Thomas Clarkson toured the ports, interviewing sailors and collecting shackles and ship records. The Society’s print of the Brookes slave ship, showing captives packed like cargo, appeared in 1788.

Pitt also ordered a committee of the Privy Council to investigate the trade. Its long report, published in April 1789, gave Wilberforce an official body of evidence to work from. Illness had kept him away in 1788, when Pitt introduced a motion to consider the subject, and Parliament passed only Dolben’s Act, which limited how many captives a ship could carry.

The speech

On 12 May 1789 the Commons sat as a committee of the whole House to consider the trade. Wilberforce chose a careful, unaggressive tone. Rather than blaming slave traders alone, he argued that the whole nation shared responsibility for allowing the trade to continue.

Drawing on the Privy Council report and on testimony collected by Clarkson, he then took the House through the evidence: how people were captured in Africa through war and kidnapping, the misery of the Middle Passage, and the death rates on board. He stressed that the trade also killed large numbers of British seamen, an argument aimed at MPs who cared more about the navy than about Africans. He rejected the claim that the West Indian colonies would collapse without new captives, arguing that better treatment would allow the enslaved population to grow naturally.

He closed by moving twelve resolutions summarising the case. Pitt, Charles James Fox and Edmund Burke all supported him. Burke praised the speech as equal to anything in the history of oratory, and many listeners judged it one of the finest the House had heard.

Why Parliament delayed

The trade’s defenders included MPs tied to the Caribbean planters and to the ports of Liverpool and Bristol, such as Bamber Gascoyne, one of the members for Liverpool. They did not try to win the argument that day. Instead they insisted that the Commons should hear its own witnesses rather than rely on the Privy Council report, a reasonable-sounding request that bought them time. The House agreed, and the matter was postponed.

The hearings ran through 1790 and into 1791. When Wilberforce finally brought a bill to abolish the trade in April 1791, it was defeated by 163 votes to 88. Events abroad hardened opposition. The French Revolution made many MPs suspicious of any radical change, and the great slave revolt in Saint-Domingue in 1791, the start of the Haitian Revolution, was used to argue that agitation endangered the colonies.

In 1792 the Commons voted for “gradual” abolition, but the House of Lords stalled. From 1793 Britain was at war with revolutionary France, and abolition was widely seen as unpatriotic or dangerous. Wilberforce kept introducing motions almost every year; in 1796 one failed by just 74 votes to 70.

Consequences

The breakthrough came after Pitt’s death in 1806. The government of Lord Grenville first banned British trading in captives to foreign and conquered colonies, then introduced a general bill. In February 1807 the Commons approved it by 283 votes to 16, and the Slave Trade Act received royal assent on 25 March 1807, taking effect on 1 May. Slavery itself continued in British colonies until the Slavery Abolition Act of 1833.

Timeline

• 1787, May: The Society for Effecting the Abolition of the Slave Trade is founded; Wilberforce agrees to lead in Parliament.
• 1788, July: Dolben’s Act regulates the number of captives per ship.
• 1789, April: The Privy Council committee publishes its report on the trade.
• 1789, 12 May: Wilberforce’s speech and twelve resolutions in the Commons.
• 1791, April: First abolition bill defeated by 163 votes to 88.
• 1792, April: Commons votes for gradual abolition; the Lords delay.
• 1807, 25 March: The Slave Trade Act receives royal assent.

Why it matters

The 1789 speech turned the evidence gathered by campaigners into a parliamentary cause and made Wilberforce its public face. Its immediate failure showed how strong the slave-trading interest was, and how long persistent campaigning inside and outside Parliament had to continue before Britain abandoned the trade.