Holy Trinity Clapham, an 18th-century Georgian church overlooking the park, is important in the history of the evangelical Clapham Sect. The Clapham Sect or Clapham Saints were a group of Church of England social reformers based in Clapham, London, at the beginning of the nineteenth century (active 1780s–1840s).



The members of the Clapham group were chiefly prominent and wealthy evangelical Anglicans who shared common political and social views concerning the liberation of slaves, the abolition of the slave trade and the reform of the penal system, amongst other issues, and who worked laboriously towards these ends over many years, motivated by their Christian faith and concern for social justice and fairness for all.