Britain Outlaws the Slave Trade, Though Not Slavery Itself
The Slave Trade Act of 1807 bans British ships from the trade after twenty years of Clarkson and Wilberforce's campaign, but leaves existing slavery in place
Quick facts
- Royal assent
- March 25, 1807
- Effective date
- May 1, 1807
- Key campaigners
- William Wilberforce, Thomas Clarkson
- Scope
- Banned the trade; did not free existing enslaved people
What happened
After two decades of campaigning by the Society for Effecting the Abolition of the Slave Trade, Prime Minister Lord Grenville introduced the Slave Trade Abolition Bill in the House of Lords on January 2, 1807. Its introduction by the head of government marked abolition as official policy for the first time, and the bill passed its second reading in the Lords 100 votes to 34 despite opposition from peers with financial interests in West Indian plantations. William Wilberforce, who had led the parliamentary campaign since 1787 after being persuaded by Thomas Clarkson's research, steered the bill through the Commons. The bill received royal assent on March 25, 1807, making it illegal from May 1, 1807 for any British ship or subject to trade in enslaved people, though it did not free a single person already enslaved in Britain's colonies.
Why it matters
The 1807 act removed Britain, then the trade's dominant carrier, from the transatlantic slave trade entirely, forcing other nations to either follow suit or continue the trade under greater international pressure and, eventually, Royal Navy interdiction. It left slavery itself legal throughout the British Empire for another 26 years, meaning abolitionists' fight was only half finished, and the domestic use of enslaved labor in British colonies continued essentially unchanged.
How we know
UK Parliament's own historical archive documents the bill's legislative path, vote counts, and royal assent date using surviving parliamentary records from the period.
Sources
- UK Parliament, Living Heritage. Parliament abolishes the slave trade · Primary source (author-declared)parliament.uk · Cited as a "primary" source (no stronger domain match).
- UK Parliament, Living Heritage. The abolitionists · Reputable sourceparliament.uk · The domain "parliament.uk" is on our Reputable source registry.
- Library of Congress. An Act for the Abolition of the Slave Trade, 25th March 1807 (Library of Congress exhibition) (1807) · Primary source (author-declared)loc.gov · Cited as a "primary" source (no stronger domain match). · Link is live and its text matches the event's key terms (Jul 2026)
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Related timelines
- The British Empire → · The Slave Trade Act removed Britain from the trade it had dominated for half a century, though slavery itself would remain legal in British colonies for another 26 years.