Amazing Grace is autobiography compressed into hymnody. John Newton went to sea as a boy, was pressed into the navy, flogged for desertion, and ended up in the Atlantic slave trade, eventually captaining slave ships. In March 1748, aboard a foundering vessel in a storm, he cried out for mercy, and marked the date ever after as the beginning of his conversion, though he continued in the trade for several more years, a fact he later confronted publicly.
Ordained in the Church of England after long refusal, he became curate of Olney, a lace making village where he wrote hymns for his weeknight prayer meetings in partnership with the poet William Cowper. Amazing Grace was written for the New Year sermon at the start of 1773, on a text from Chronicles in which David marvels at what God has done for him, and it was published in their joint collection, Olney Hymns, in 1779 under the heading Faith's Review and Expectation. Its six stanzas run Newton's story in miniature, lost and found, blind and seeing, through many dangers, toils and snares. In old age Newton supported Wilberforce, published a blunt pamphlet confessing the horrors of the trade he had served, and lived to see abolition of the British slave trade in 1807, the year he died. The epitaph he wrote for himself begins, John Newton, clerk, once an infidel and libertine.