You mention in your new PBS show a story about John Newton and how he became an ardent anti slave trader after a miracle at sea. What is the source for your story? ^ Adam Hochschild. Bury the Chains. Basingstoke: Pan Macmillan, 2005. 77.He did not renounce the slave trade until later in his life. After his return to England in 1750, he made three further voyages as captain of the slave-trading ships Duke of Argyle (1750) and African (1752–1753 and 1753–1754). He only gave up seafaring and his active slave-trading activities in 1754, after suffering a severe stroke, but continued to invest his savings in Manesty's slaving operations."