The immediate effect of the Zong massacre on public opinion is limited, demonstrating—as the historian of abolitionism Seymour Drescher has noted—the challenge that the early abolitionists face.

Following Sharp's efforts, the Zong massacre will become an important topic in abolitionist literature and the massacre is discussed in works by Thomas Clarkson, Ottobah Cugoano, James Ramsay and (from 1788) John Newton.

The Zong killings offer a powerful example of the horrors of the slave trade, stimulating the development of the abolitionist movement in Britain, which dramatically expands in size and influence in the late 1780s.

In 1787, the Society for the Abolition of the Slave Trade is founded.

Cugoano, possibly with the help of his friend Olaudah Equiano, publishes an attack on slavery entitled Thoughts and Sentiments on the Evil and Wicked Traffic of the Slavery and Commerce of the Human Species (1787).

By now a devout Christian, he writes work informed by this religion.

His writing calls for the abolition of slavery and immediate emancipation of all slaves.

It argues that the slave's duty is to escape from slavery, and that force should be used to prevent further enslavement.

The narrative is sent to King George III, the Prince of Wales and to Edmund Burke, a leading politician.

George III, along with much of the royal family, remains opposed to abolition of the slave trade.

The first anti-slavery statement by Dutch and German Quakers had been signed in 1688 at Germantown, Pennsylvania.

Following this, English Quakers had begun to express their official disapproval of the slave trade since 1727 and promote reforms.

A number of Quakers in Britain's American colonies had from the 1750s also begun to oppose slavery, calling on English Quakers to take action, and encourage their fellow citizens, including Quaker slave owners, to improve conditions for slaves, educate their slaves in Christianity, reading and writing, and gradually emancipate them.

An informal group of six Quakers had pioneered the British abolitionist movement in 1783 when the London Society of Friends' yearly meeting presented its petition against the slave trade to parliament, signed by over three hundred Quakers.

They had subsequently decided to form a small, committed, non-denominational group so as to gain greater Anglican and Parliamentary support.

The new, non-denominational committee formed in 1787 has nine Quaker members (who, as non-conformists, are debarred from standing for Parliament), and three Anglicans, whose support strengthens the committee's likelihood of influencing Parliament.

Nine of the twelve founding members of the Society for Effecting the Abolition of the Slave Trade are Quakers: John Barton; William Dillwyn; George Harrison; Samuel Hoare Jr; Joseph Hooper; John Lloyd; Joseph Woods Sr; James Phillips; and Richard Phillips.

Five of the Quakers had been among the informal group of six Quakers who had pioneered the movement in 1783 when the first petition against the slave trade was presented to parliament.

The tree Anglicans who co-found the committee are Thomas Clarkson, campaigner and author of an influential essay against the slave trade; Granville Sharp who, as a lawyer, had long been involved in the support and prosecution of cases on behalf of enslaved Africans; and Philip Sansom.

The Society for Effecting the Abolition of the Slave Trade (or the Society for the Abolition of the African Slave Trade) is on May 22, 1787, formed in London.

The mission of the Society is to inform the public of the inhuman and immoral treatment of enslaved Africans committed in the name of slavery, to campaign in favor of a new law to abolish the slave trade and enforce this on the high seas, and to establish areas in West Africa where Africans could live free of the risk of capture and sale into slavery.

It will pursue these proposals vigorously by writing and publishing antislavery books, abolitionist prints, posters and pamphlets, and organizing lecture tours in the towns and cities of England.

Petitions are presented to the House of Commons, antislavery rallies held, and a range of antislavery medallions, crockery and bronze figurines are made, notably with the support of the Unitarian Josiah Wedgwood, whose production of pottery medallions featuring a slave in chains with the simple but effective question: Am I not a man and a brother? is very effective in bringing public attention to abolition.

The Wedgwood medallion is the most famous image of a black person in all of eighteenth-century art.

Thomas Clarkson writes; "ladies wore them in bracelets, and others had them fitted up in an ornamental manner as pins for their hair. At length the taste for wearing them became general, and thus fashion, which usually confines itself to worthless things, was seen for once in the honourable office of promoting the cause of justice, humanity and freedom".

By informing the public, the Committee for the Abolition of the Slave Trade gained many members.

Public interest is generated immediately after the Committee forms in 1787 by Clarkson's tour of the great ports and cities of England.

Parliament has received numerous petitions against the slave trade and examines the issue in 1788.

With strong support by Sir William Dolben, who had toured a slave ship, it passes the Slave Trade Act 1788 (Dolben's Act), which is its first legislation to regulate the slave trade.

It restricts the number of slaves that can be transported, to reduce problems of overcrowding and poor sanitation.

The public mood in Britain is very shortly further aroused against slavery by the work of the formerly enslaved African whose autobiography, The Interesting Narrative of the Life of Olaudah Equiano, or Gustavus Vassa, the African, demonstrates both literary skill and an unanswerable case against slavery.

Published in London, it is one of the earliest published works by a black writer.

Clarkson is able to promote the Committee's cause in 1789 by encouraging the sale of Equiano's first-hand account of the slave trade and slavery abroad, and his visits to British ports linked to the trade.

Cugoano publishes a shorter version of his book, addressed to the "Sons of Africa", in 1791.

In it, he expresses qualified support for the failed British efforts to establish a colony in Sierra Leone for London’s Poor Blacks (mostly freed African-American slaves who had been relocated to London after the American Revolutionary War. Other early settlers are Black Loyalists, also former American slaves, from Nova Scotia, who choose to move to Sierra Leone.)

Cugoano calls for the establishment of schools in Britain especially for African students.

Nothing is known of Cugoano after the release of his book.

The importation of slaves into the United States is banned on January 1, 1808, as the 1806 Act Prohibiting Importation of Slaves takes effect; African slaves will continue to be imported into Cuba, and until Cuba abolishes slavery in 1865, half a million slaves will arrive on the island.

The laws that ultimately end the Atlantic triangle trade come about as a result of the efforts of abolitionist religious groups such as the Society of Friends, known as Quakers, and Evangelicals led by William Wilberforce, whose efforts through the Committee for the Abolition of the Slave Trade leads to the passage of the Slave Trade Act by the British Parliament in 1807.

This leads to increased calls for the same ban in America, supported by members of the U.S. Congress from both the North and the South as well as President Thomas Jefferson.

At the same time that the importation of slaves from Africa is being restricted or eliminated, the United States is undergoing a rapid expansion of cotton, tobacco, sugar cane and rice production in the Deep South and the West as a result of increased immigration, largely from Northern Europe.

Slaves are treated as a commodity by owners and traders alike, and are regarded as the crucial labor for the production of lucrative cash crops that feed the triangle trade.

The slaves are managed as assets in the same way as chattel; slaveholders pass laws regulating slavery and the slave trade designed to protect their financial interests; there is little protection for the slaves.

Separating slave families for the purposes of assigning workers to the task for which they are best physically suited is a common practice.

In addition to agriculture, slave labor is increasingly used in mining, shipbuilding and other industries.

The federal government had criminalized the international slave trade in 1808, limiting the supply of slaves in the United States, but after 1820 cultivation of the highly profitable cotton crop explodes in the Deep South, and along with it, the slave population.

The invention of the cotton gin has enabled expanded cultivation in the uplands of short-staple cotton, leading to clearing lands cultivating cotton through large areas of the Deep South, especially the Black Belt.

The demand for labor in the area increases sharply and an internal slave market expands.

At the same time, the Upper South has an excess supply of slaves because of a shift to mixed crops agriculture, which is less labor intensive than tobacco.

Planters in the Upper South states start selling slaves to the Deep South, generally through slave traders.

During this period, the terms "breeding slaves", "child bearing women", "breeding period", "too old to breed", etc., begin to become familiar.

Slave breeding is becoming a common practice among slave holders and plantation owners as a result of several factors, including fears of rebellion from the increasing numbers of newly arrived slaves from Africa, and the economic impact caused by newly passed laws that restrict or eliminate the importation of slaves to Britain and the United States.