In the late 18th century , opposition to slavery was increasing . Many abolitionists were aroused by the Zong massacre , whose details became known during litigation in 1783 , when the syndicate owning the ship filed for insurance claims to cover 132 – 142 slaves who had been killed . Quakers had been active in petitioning Parliament to end the trade . To expand their influence , in 1787 they formed a non-denominational group , the Society for the Abolition of the Slave Trade , which included Anglicans of the established church ( non-Anglicans were excluded from Parliament )
Zong massacre
Zong massacre
Slave Trade Act 1788