This hymn and the story behind it are so powerful. Horatio Spafford was a lawyer who lived in the latter half of the nineteenth century. In a four-year span, his life was turned completely upside down. He lost his only son in 1870, then in 1871, the Great Chicago fire burned down the city, and he lost most of his assets. Finally in 1873, he sent his wife and daughters to England on holiday, only to receive a telegram from his wife saying "saved alone." The boat that they were on had gotten caught in a storm, and all four of Spafford's daughters died. As he sailed to England to join his wife, he penned this hymn when the ship passed over the spot where the boat carrying his family had sunk.
