Mary Baker Eddy (; July 16, 1821 – December 3, 1910) was an American religious leader and author who founded The Church of Christ, Scientist, in New England in 1879. She also founded The Christian Science Monitor in 1908, and three religious magazines: the Christian Science Sentinel, The Christian Science Journal, and The Herald of Christian Science. She wrote numerous books and articles, the most notable of which were Science and Health with Key to the Scriptures and Manual of The Mother Church. Other works were edited posthumously into the Prose Works Other than Science and Health.
Eddy was born Mary Morse Baker on July 16, 1821, in a farmhouse in Bow, New Hampshire, to farmer Mark Baker (d. 1865) and his wife Abigail Barnard Baker, née Ambrose (d. 1849). Eddy was the youngest of six children: boys Samuel Dow (1808), Albert (1810), and George Sullivan (1812), followed by girls Abigail Barnard (1816), Martha Smith (1819), and Mary Morse (1821). She was also the cousin of U.S. Representative Henry M. Baker.
She was the sixth generation of her family born in the United States. The farmhouse she was born in was built by her grandfather, Joseph Baker Jr., on a tract of land his maternal grandfather, Captain John Lovewell, had been given for service in the American Revolutionary War. Eddy's father Mark inherited, alongside his elder brother James, the farm when Joseph Jr. died in 1816.
Mark Baker was an active member of the Tilton Congregationalist Church. McClure's reported he had a reputation for holding strong opinions and quarrelling with those he disagreed with; one neighbor described him as "[a] tiger for a temper and always in a row." They also reported he was an ardent supporter of slavery and a Copperhead who was reportedly pleased to hear about Abraham Lincoln's death. Despite trying to oust his Republican pastor during the war alongside a faction of his church, he refused to leave the church alongside other members of the faction when they failed. Instead, he continued to attend services, but would storm out at the mention of the American Civil War during a service.