In 1787 a small, mainly Quaker group led by Thomas Clarkson (1760-1846) formed The Society for the Abolition of the Slave Trade. Their cause seemed hopeless as slavery was crucial to Britain's economy but popular feeling was on their side. The French Revolution and the backlash against British Radicalism temporarily stalled the campaign for anti-slavery campaign. The Society's Parliamentary spokesman William Wilberforce finally oversaw the triumphant passing of the Abolition of the Slave Trade Act in 1807. The Great Reform Act of 1832 swept away many of the old pro-slavery MPs and the final emancipation of slaves in British colonies was effected in 1833.