Although Denmark was actually the first European country to abolish the slave trade in 1802, England and the northern United States are credited with being at the forefront of ensuring the abolition of the trans-Atlantic slave trade in all European and New World countries. There were many factors involved with the abolition of the slave trade and the emancipation of slaves in the nineteenth century, and this area is one of the most debated aspects in the study of the slave trade today. Generally, a combination of ideas gleaned from the late eighteenth century Enlightenment and changing economic and religious sensibilities, as well as the efforts of Africans themselves, all combined to produce strong anti-slavery campaigns in Europe and in the Americas.

As early as 1694, Captain Thomas Phillips remarked: “I can’t think there is any intrinsick value in one colour more than another, not that white is better than black, only we think so because we are so, and are prone to judge favourably in our own case.” The first real attack on slavery came in the early eighteenth century from the non-conformist religious groups, particularly the Quakers. The Quakers had emerged as a religion after the English Revolution of 1688 and held a strong belief in democratic ideas, believing that the light of God’s truth worked in every man and woman. The Enlightenment of the eighteenth century, which aimed for rationality and gradual transformation of the human condition, admired the Quakers’ principles; however, many of the Enlightenment thinkers were ambivalent to the problem of slavery in the world. Most philosophers agreed that in an ideal world slavery would not exist, but thinkers such as Voltaire, knowing that the world was far from ideal, thought that slavery was, perhaps, inevitable. In spite of these vacillations, early Enlightenment thinkers are credited with bringing the topic of slavery to the foreground of public discussion in Europe. By the second half of the century, philosophes were launching stronger attacks against the practice, although there was still much ambiguity. A 1755 volume of the Encyclopedia condemned slavery as a violation of the natural rights of every human being:

Although many of the Enlightenment figures were writing in France, England had its own radical writers, especially the reforming and humane sensibility of writers, such as John Wilkes, of the 1760s and 70s.

The American Revolution from 1776 to 1783 and the French Revolution of 1789 took the reforming ideas of the Enlightenment thinkers and made them a physical reality. These revolutions fostered anti-slavery ideas, and even though the expansion of the cotton economy in the Southern United States resulted in anti-slavery movements being pushed aside in favour of economic advancement, these ideas were to have a much more immediate impact in Europe and elsewhere. The Haitian Revolution, which resulted in the destruction of French colonial society, was borne of the ideas of the French Revolution, which was itself partially spurred by the actions of the Americans. Although the chaos resulting from the revolution in Haiti put a temporary damper on the popularity of the anti-slavery movement, it was only a brief setback. After the launching of the anti-slavery movement by evangelicals in 1787, people began attaching their names to anti-slavery petitions in unprecedented numbers, surprising even the founding fathers of the movement with its popularity. The growth of the non-conformist movement played a significant role in Britain’s decision to abolish the slave trade in 1807, although the institution of slavery itself continued.

A skilful and effective propaganda campaign aided abolitionists in their fight, which included the wide dissemination of literature and pamphlets documenting the many horrible details and statistics concerning the slave trade. They began recording the stories of escaped or free slaves in an effort to reveal the realities of slave life, which were also very popular. One of the most famous of these slave narratives is that of The Interesting Narrative of the Life of Olaudah Equiano or Gustavus Vassa the African, which was written by himself and appeared in 1789. The work was immediately reviewed as “calculated to increase the odium that has been excited against the West Indian planters”. For their part, the pro-slavery campaigners argued the necessity of the trade to economic prosperity and national productivity, and stressed the “natural” inferiority of Africans to Europeans and the justification that Africans would never be productive unless forced to work through slavery. These arguments, however, were becoming increasingly drowned out by voices sympathetic to the plight of slaves as the century progressed.

Although abolitionists concentrated primarily on stressing the immorality and cruelty of the slave trade, anti-slavery arguments were also bolstered by a changing economic landscape. Both the Northern United States and England were enjoying unprecedented urban and economic growth and an increase in domestic consumption, tended to see this growth as the result of a free labour system. More industrialised and progressively-minded areas of these countries, particularly the northern United States, which did not rely as immediately on a large quantity of slave labour, began putting pressure on rural areas to look for alternate labour markets, assuming that the use of slaves was an economic anachronism. Of course, these incipient industrial areas relied on the produce coming from the labour of slaves in the country, a fact of which rural slave-owners were very aware. The English, for their part, were looking to expand their markets for manufactured goods on a large scale, and wanted to trade with Africa for their natural resources, rather than slaves. The 1807 abolition of the slave trade had had significant repercussions on English planters in the West Indies. Rather than treating their slaves better, slave owners faced with a diminishing labour force often relegated more highly skilled slaves to more arduous manual labour. These tensions, plus the information filtering in about the anti-slavery movement from abroad, played significant roles in the slave revolts of 1816, 1823, and 1831. Faced with imminent labour shortages, slave-owners also had to look for alternate labour markets, particularly to Asia and India for large numbers of workers. Manufacturers and shippers who were affected by the abolition of the slave trade had a growing range of alternate markets to develop, which promised to be even more profitable.

The trans-Atlantic slave trade was abolished by Britain in 1807, and by the late 1820’s popular support was growing to end the institution of slavery in Britain entirely. Tens of thousands of people signed their names on petitions to MPs, who were persuaded to support abolition. The 1832 Reform Act in the English parliament changed the make-up of the parliament itself, which afterwards included a greater number of members who were sympathetic to abolition. Emancipation came in stages beginning in 1834 some slaves were completely freed while others had to work for their previous owners for a certain number of hours per week. All slaves in English colonies were freed in 1838.

The abolition of the slave trade and slavery by England did not meet with unanimous decisions by other nations, although the Dutch had stopped slave trading by 1814. The United States had technically abolished the slave trade along with England in 1807, however because slave populations within the country increased naturally, there was less reliance on the overseas trade. Slavery continued and was encouraged as well because of the profitability of the burgeoning cotton market. The use of slaves was still very profitable in the colonies and trade continued in spite of English efforts to enforce abolition on its European neighbours and the African states with which it had conducted its trade. More Africans were carried across the Atlantic after 1807 than in the previous century, largely because of an economic boom in Cuba and Brazil, which demanded increasing numbers of slaves. Slavery in the United States fractured the country between a largely abolitionist-minded North and slave owners in the South. Slavery had become the most pressing political issue by the mid-nineteenth century, which was not resolved until the Emancipation Proclamation of 1863, after the secession of the South and the Civil War.

In some cases other European nations who abolished slavery did so with no great loss to themselves, their economies not relying heavily on slavery. The Portuguese, although more dependent on the labour of slaves, were pressured into ending slavery in 1836. Sweden and Denmark, who were not as reliant on the institution, followed suit in 1847 and 1848, respectively, France in 1848, and The Netherlands abolished slavery in 1863. In South America, the upheavals caused by the colonies’ bid for independence from Europe often secured the involvement of the slaves with promises of freedom, and the democratic ideals eschewed by the colonists were no less valuable in ensuring the freedom of the slaves. Nearly all of the newly formed revolutionary governments abolished slavery in the first decade after independence. The exceptions to this trend were Cuba and Brazil, where independence actually strengthened the institution, largely due to a massive increase in the countries’ production of sugar, tobacco (in Cuba), and coffee (in Brazil). The war in the United States had repercussions for the slaves in Cuba, leading to open rebellion and weakening the institution. Cuba finally emancipated its slaves in 1886. Growing criticism of slavery within Brazil began as the result of international attacks on the Brazilian slave trade, particularly by England. Although the country ended the slave trade in 1850, slaves were not entirely freed there until 1888.