History of the Negro race in America from 1619 to 1880. Negroes as slaves, as soldiers, and as citizens; together with a preliminary consideration of the unity of the human family, an historical sketch of Africa, and an account of the Negro governments of Sierra Leone and Liberia Williams, George Washington, 1849-1891
Considerations on the Continuance of the Slave Trade, and of the Use of Slaves in the British Colonies (1788) Anonymous (likely a British abolitionist influenced by Quaker or Anglican theology)
Essai sur l'Histoire Religieuse des Nations Slaves (traduit de l'anglais) Valerian, Count, approximately 1780-1855 Krasinski