While the United States recently made Juneteenth its newest federal holiday to commemorate the end of slavery, another date was previously celebrated by U.S. abolitionist societies: Aug. 1.

That date, in 1834, marked the end of slavery in the British Empire, when the 1833 Abolition of Slavery Act came into force. In many of Britain’s former colonies in the Caribbean, as well as Canada, Aug. 1 is still celebrated as Emancipation Day.

Yet Emancipation Day commemorates a struggle to overcome slavery that did not end with its abolition. Rebellions against slavery, in Barbados in 1816, Demerara (later a part of British Guiana) in 1823 and Jamaica in 1831-32 forced Parliament toward granting emancipation. But the freedom enslaved people received on Aug. 1 was not the autonomy and dignity for which they had fought. In fact, in key ways antislavery sentiment and policies helped disguise — and prolong — the exploitation of formerly enslaved people. After slavery, freed people were denied access to land and expected to work for low wages. Emancipation policies also proved to be a useful justification for imperialism.

The Caribbean was the center of British imperial political economy in the 18th century. Between 1619 and the abolition of the British slave trade in 1807, at least 365,563 enslaved people disembarked in British North America and what would become the United States of America. By comparison, more than 2,221,000 enslaved people disembarked in Britain’s sugar-producing colonies in the Caribbean, including more than 1 million people in Jamaica alone.

Sugar production and slavery went hand in hand. Sugar cane juice spoils quickly. Cutting and processing canes required large, heavily disciplined workforces of enslaved people toiling in horrific conditions, sometimes in near darkness, among large fires and heavy machinery.

Demand for sugar was inexhaustible. While enslaved people produced it, some Caribbean enslavers became incredibly rich and retired to Britain to manage their plantations from the comfort of a chic townhouse or country estate.

Enslaved people opposed slavery from its beginning, dramatically in armed rebellions on slave ships and plantations, and subtly by emptying stores, slowing work or satirizing the authority that enslavers claimed over them.

Opposition to slavery was a fact of life among enslaved people, but growing imperial power prompted Britons to examine their consciences. Some worried that the horrors of mass enslavement didn’t suit a “mature” empire. Others worried that slavery impeded Britain’s ability to spread the Gospel. Still others argued that slavery was economically inefficient, and that Britain’s empire would be better served by cheap wage labor on sugar plantations and aggressive investment in raw materials produced in West Africa.

Rather than supporting enslaved rebels in the colonies, the leaders of Britain’s antislavery movement argued that rebellion proved that enslaved people required “civilization” to prepare them for freedom. One abolitionist wrote that enslaved people “know and feel nothing of society, but the hardships and punishments that it cruelly and capriciously inflicts.” Emancipation, by these lights, needed to be gradual to end slavery without disturbing the social hierarchy.

In 1807, Britain abolished its slave trade, the culmination of a long campaign in Parliament and in Britain’s growing civil society. However, the Slave Trade Act was passed during the decades-long war with Napoleonic France, and Britain hoped it would serve as an economic weapon to harm the rival empire. From 1791 to 1804, France had fought against enslaved and free Black rebels in Saint-Domingue, its most valuable sugar-producing Caribbean colony, in a war that ended with the independence of Haiti.

After the Haitian Revolution, France was no longer a serious rival to Britain in the Caribbean, and defenders of the slave trade could no longer claim that abolishing the trade would give France an advantage.

Antislavery leaders in Britain argued that without the slave trade, colonial legislatures in the Caribbean would work to improve living and working conditions for enslaved people, opening a long and gradual path to emancipation. As an antislavery leader put it in the House of Commons, emancipation would come “in a course of years, first fitting and qualifying the Slave for the enjoyment of freedom … nothing rash, nothing rapid, nothing abrupt.”

But conditions for enslaved workers did not improve. And enslaved people — aware of colonial and imperial politics — imagined that London was ready to grant emancipation against the wishes of furious colonial legislators. They sometimes timed rebellions to take advantage of what seemed like head winds of metropolitan support for their cause.

However, to the elite of the antislavery movement in Britain, gradual emancipation was supposed to suppress, not encourage, revolution. In an 1824 speech to the House of Commons, a leading politician compared Black freedom to Frankenstein’s monster, a creature “possessing the form and strength of a man, but the intellect only of a child.” Imperial antislavery foreclosed on an emancipation shaped from below.

In 1831-32, over Christmas and the new year, Samuel Sharpe, an enslaved Baptist deacon, led a rebellion in Jamaica. The “Baptist War,” which began as a work stoppage and a demand for wages, was among the largest slave revolts in history. When the militia was summoned, enslaved workers took up arms. The reprisal was swift and brutal, and Sharpe was hanged.

Sharpe’s courage is celebrated on Emancipation Day; he is a national hero in Jamaica. But the way British missionaries portrayed Sharpe shows the gulf between the revolutionary spirit of Emancipation Day and the limits of imperial emancipation policy. Long after the rebellion, the missionary Henry Bleby gave a speech in Massachusetts. Like Jesus, he recalled, Sharpe sacrificed himself, “in order that the rest may be free.” British antislavery activists focused on Sharpe’s death, rather than his demands for freedom and fair wages.

But the Baptist War did force the issue of emancipation, and in 1833 Parliament passed the Abolition of Slavery Act. The act was designed to preserve the imperial sugar industry and affirm the inviolability of property, even as it proclaimed that human beings could not be property. No longer “enslaved,” the hundreds of thousands of people working the plantations of the sugar empire were now considered “apprenticed.” As apprentices, freed people were expected to continue to work without wages for up to six years. Former enslavers, meanwhile, received 20 million pounds in government compensation for the loss of their “property.”

Sugar receipts fell, particularly after the end of apprenticeship in 1838. Freed people were blamed for “failing” the empire. Legislation kept wages low, and land prices high. When people of African descent earned enough to stand for office, colonial legislatures raised the bar for the franchise to exclude them. Even as freed people challenged colonial power, the fact that Britain had abolished slavery at all became a cudgel. Grievances were dismissed as “ingratitude” to an empire that had, after all, ended slavery.

Meanwhile, Britain continued to profit from slavery. Britain purchased nearly all of America’s cotton, grown by enslaved people, and opened British markets to sugar manufactured in Cuba and Brazil, where slavery remained crucial to the plantation economy.

For British and American abolitionists, the dependence of British industry on cotton became a conundrum that was ultimately resolved by force, during the cotton blockade of the American Civil War. “The manufacture of cotton,” one activist worried, “is so intimately bound up with the interests of this country,” that divestment from American cotton would tank the economy.

After the American Civil War, in the last decades of the 19th century, Britain expanded its territorial empire in Africa, using its antislavery bona fides to impose its will on African states and justify the plunder of natural resources from the continent. Moreover, plantations survived the abolition of slavery. Free labor plantations growing cash crops, including cotton, worked by exploited and dispossessed people, mushroomed throughout the empire, and remain a feature of political economy in the global South.

On Aug. 1, 1857, in Canandaigua, N.Y., Frederick Douglass — who had toured Britain several times, to enthusiastic crowds — weighed Britain’s achievements in the fight against slavery. The British Empire had “made the name of England known and loved in every Slave Cabin,” he said, and “spread alarm, hatred, and dread in all the accursed slave markets of our boasted republic.” But freedom for Black people remained elusive. The formal policy shift, rooted in imperialism, capitalism and coercion that occurred on Aug. 1, 1834, was something very different from the struggle for freedom celebrated on Emancipation Day.