Along with the founding committee, which included the Anglican Thomas Fowell Buxton, the Quaker William Allen, and the Congregationalist Josiah Conder, they organised the first World Anti-Slavery Convention in London in 1840,[10] that attracted delegates from around the world (including from the United States of America, in the South of which slavery was at times referred to as "our peculiar institution") to the Freemasons' Hall, London on 12 June 1840.

Many delegates were notable abolitionists, with Thomas Clarkson the key speaker, and the image of the meeting was captured in a remarkable painting that still hangs in the National Portrait Gallery in London.

Convention leaders refused to seat the women delegates from America, and prominent male abolitionists such as Thomas Knight were outraged.

[citation needed] In the 1850s, under Louis Chamerovzow, the society helped John Brown write and publish his autobiography a decade before the American Civil War ended slavery in the United States.

At the beginning of the 20th century Anti-Slavery Society campaigned against slavery practices perpetrated in the Congo Free State by King Leopold II of Belgium.

In 1921 Played a pivotal role in ending the activities of the Peruvian Amazon Company, which was using indigenous slave labour in rubber production.

[23] By the 1950s, legal chattel slavery and slave trade was formally abolished by law in almost the entire world, with the exception of the Arabian Peninsula.

[26] The Kennedy administration also experienced international pressure from influential secular Middle East regional leaders like Gamal Abdul Nasser, as well as from the newly decolonization African states, whose own citizens were the most common victims of the slave trade to the Arabian Peninsula,[26] and whose good will was necessary Kennedy's anti Soviet New Frontier agenda in the Global South.

[27] The Kennedy administration therefore put pressure on Saudi Arabia to introduce "modernization reforms", a request which was heavily directed against slavery.

[6] Anti-Slavery International was one of the original supporters of the "End Child Prostitution, Pornography and Trafficking" campaign (ECPAT), and helped set up the UK branch in the 1990s.

The ruling set a legal precedent with respect to the obligations of states to protect its citizens from slavery[28] In June 2010, following the campaign by Anti-Slavery International and Liberty the UK Parliament introduced a criminal offence of forced labour in the Coroners and Justice Act 2009.

[citation needed] In 2010 the organisation also exposed the routine use of the forced labour of girls and young women in the manufacture of garments in Southern India for Western high streets, prompting, eventually, business and international civil society efforts to end the practice.

Anti-Slavery lobbied the UK government to sign up to an EU anti-trafficking law to protect the victims and secure justice for people who have been trafficked (2011).

It also played a big part in lobbying the International Labour Organization to adopt a Convention on Decent Work for Domestic Workers in June 2011.

[29] Human trafficking is the illegal transportation of kidnapped people, including children, across international borders in order to put them into slavery at the destination.

[31] The organization joined more than 180 other groups in a campaign to pressure retailers such as Nike, Apple and Gap to stop using forced labour of Uighurs in their factories located in China.