The origin of the song "Amazing Grace" comes from John Newton, a slave trader, who wrote the hymn in 1772. The words for Amazing Grace were published in "Olney Hymns" in 1779. In 1835, William Walker, set the words to the song "New Britain."
Newton, who endured a life at sea from 1736 to 1754 converted to Christianity following survival during a storm at sea. He gradually changed his ways and took to reading the bible, but not before continuing to make slave trading voyages before retiring in 1754. During retirement he became an ordained Anglican priest and wrote over 280 hymns for his services.