An appeal to the religion, justice, and humanity of the inhabitants of the British Empire in behalf of the Negro slaves in the West Indies, 1823 title page (Wm. Wilberforce, Esq., M.P.)
English Wikipedia website, viewed June 12, 2012 (William Wilberforce (24 August 1759-29 July 1833) was a British politician, philanthropist, and a leader of the movement to abolish the slave trade. A native of Kingston upon Hull, Yorkshire, he began his political career in 1780, eventually becoming the independent Member of Parliament for Yorkshire (1784--1812); died London, England)
His A letter on the abolition of the slave trade, 1807 t.p. (W. Wilberforce)