In 1805, after some years of assisting the Society for the Abolition of the Slave Trade, William Allen was elected to its committee. The society had always been strongly influenced by Quakers, and particularly by those based in or near London. All the members of its predecessor committee (1783–1787) had been Quakers, and nine of the twelve founders of the subsequent non-denominational Society for the Abolition of the Slave Trade were Quakers, including two – Samuel Hoare Jr and Joseph Woods Sr (father of the botanist Joseph Woods Jr) – who lived close to William Allen in Stoke Newington, the village near London where Allen had family interests after his second marriage in 1806.