Banning the trade did not free a single person already enslaved, and it did not stop the ships. Ending slavery itself took most of the nineteenth century, and it came through warships, parliaments, pamphlets, rebellions and, in the United States, a civil war.
Policing the ocean
After 1807 Britain tried to make other nations stop too, through treaties and force. The Royal Navy's West Africa Squadron patrolled the coast to seize illegal slave ships. Between 1808 and 1860 it captured roughly 1,600 ships and freed about 150,000 Africans, many of whom were landed at Freetown in Sierra Leone. Yet the illegal trade carried millions more after 1807, mostly to Brazil and Cuba, and patrol duty cost many British sailors their lives. Freetown, founded for freed people in 1792, grew into a community of recaptives from all over West Africa. Critics then and since have noted that Britain also used the campaign to extend its naval and imperial power in Africa.
Gradual or immediate?
British abolitionists at first hoped slavery would wither once the trade ended. It did not. In 1823 they launched a campaign for gradual emancipation. A Leicester Quaker, Elizabeth Heyrick, found that too timid. In her pamphlet of 1824, Elizabeth Heyrick demanded immediate rather than gradual abolition. Women's antislavery societies took up her call, and by the late 1820s "immediate" became the movement's watchword.
The rebels
Enslaved people forced the pace. In 1823 thousands rose in Demerara, in British Guiana. At Christmas 1831 a still larger rising began in western Jamaica, led by the Baptist deacon Samuel Sharpe, who planned a strike for wages that turned into rebellion. The Baptist War of 1831 to 1832 was a huge rising of enslaved people in Jamaica, involving perhaps tens of thousands. It was crushed, and hundreds were executed, Sharpe among them, but it convinced many in London that slavery could not last.
The British act of 1833
The Slavery Abolition Act passed in 1833 and took effect on 1 August 1834. It was a compromise. Apprenticeship forced most freed people to keep working unpaid for their former owners for several years. Protests cut it short in 1838. Meanwhile, the act gave slaveholders £20 million in compensation, about 40 percent of the government's yearly spending. The roughly 800,000 people who had been enslaved received nothing. The act did not at first cover territories ruled by the East India Company, where slavery was outlawed separately in 1843.
France and the Spanish empire
Revolutionary France abolished slavery in 1794, after the uprising in Saint-Domingue. Napoleon restored it in 1802. France finally abolished slavery in 1848, after a new revolution, led by the campaigner Victor Schoelcher. As in Britain, the former owners were compensated and the freed were not. The Netherlands followed in 1863, Spain ended slavery in Puerto Rico in 1873 and in Cuba in 1886, and Brazil in 1888.
The United States
In the United States, slavery grew stronger as cotton spread west. On 1 January 1831 William Lloyd Garrison launched his newspaper The Liberator with a promise: "I will not equivocate, I will not excuse, I will not retreat a single inch, and I will be heard." Frederick Douglass, who escaped slavery in 1838, became the movement's most powerful speaker. Harriet Tubman escaped in 1849 and returned to lead others north along the secret network called the Underground Railroad. In 1852 Harriet Beecher Stowe's novel Uncle Tom's Cabin sold hundreds of thousands of copies within a year and turned many Northern readers against slavery.
Politics hardened on both sides. The Fugitive Slave Act of 1850 required Northern officials and citizens to help return runaways, denying the accused a jury trial. In the Dred Scott case of 1857 the Supreme Court ruled that Black Americans could not be citizens. After Abraham Lincoln's election, Southern states seceded and war began in 1861. The Emancipation Proclamation of 1 January 1863 declared free those enslaved in areas in rebellion, and it opened the Union army to Black soldiers, nearly 200,000 of whom served.
Worked example: following the compensation money
Take one claimant under the 1833 act. John Gladstone, a Liverpool merchant and father of the future prime minister William Gladstone, owned estates in British Guiana and Jamaica. He received about £106,000 for more than 2,500 enslaved people, a fortune worth many millions today. The money flowed into investments in Britain, including railways and banks.
Now look at the people on his estates. On 1 August 1834 they became apprentices, still bound to work, still subject to punishment. When apprenticeship ended they were free, but most had no land, no savings and no compensation. Gladstone, worried about labor, helped bring indentured workers from India to his Guiana estates.
The case shows why historians call 1834 both a triumph and a compromise. It ended legal ownership of people across most of the British empire, peacefully and by law. It also treated the owners as the injured party. Asking who was paid, who was not and what followed is a way to judge any emancipation, from Jamaica to Texas.