One of the first protests against the enslavement of Africans came from German and Dutch
Quakers in Pennsylvania in 1688. One of the most significant milestones in the campaign to abolish slavery throughout the world occurred in
England in 1772, with British judge
Lord Mansfield, whose opinion in
Somersett's Case was widely taken to have held that slavery was illegal in England. This judgement also laid down the principle that slavery contracted in other jurisdictions (such as the American colonies) could not be enforced in England.
[213] In 1777,
Vermont became the first portion of what would become the United States to abolish slavery (at the time Vermont was an independent nation). In 1794, under the Jacobins,
Revolutionary Franceabolished slavery.
[214] There were celebrations in 2007 to commemorate the 200th anniversary of the Abolition of the slave trade in the United Kingdom through the work of the British
Anti-Slavery Society.
Joseph Jenkins Roberts, born in Virginia, was the first president of
Liberia, which was founded in 1822 for freed American slaves.
William Wilberforce received much of the credit although the groundwork was an anti-slavery essay by
Thomas Clarkson. Wilberforce was also urged by his close friend, Prime Minister
William Pitt the Younger, to make the issue his own, and was also given support by reformed Evangelical
John Newton. The
Slave Trade Act was passed by the British Parliament on March 25, 1807, making the slave trade illegal throughout the
British Empire,
[215] Wilberforce also campaigned for abolition of slavery in the British Empire, which he lived to see in the
Slavery Abolition Act 1833. After the 1807 act abolishing the slave trade was passed, these campaigners switched to encouraging other countries to follow suit, notably France and the British colonies. In 1839, the world's oldest international human rights organization,
Anti-Slavery International, was formed in Britain by
Joseph Sturge, which campaigned to outlaw slavery in other countries.
[216]
Between 1808 and 1860, the British
West Africa Squadron seized approximately 1,600 slave ships and freed 150,000 Africans who were aboard.
[217] Action was also taken against African leaders who refused to agree to British treaties to outlaw the trade, for example against "the usurping King of
Lagos", deposed in 1851. Anti-slavery treaties were signed with over 50 African rulers.
[218]
In the
United States, abolitionist pressure produced a series of small steps towards emancipation. After January 1, 1808, the importation of slaves into the United States was prohibited.