John Newton, 1725-1807: English infidel slave-trader turned abolitionist and evangelist. He served as curate at Olney for many years, where he and his friend William Cowper wrote the hymns published as "Olney Hymns" -- and from whence he carried on a heated controversy with the "Arminian" Wesleys. Although he was overshadowed as a poet by Cowper, "Amazing Grace" is surely in every English-language hymnal, and generally accompanied by several others of his hymns.