John Donihoo was born in 1775 in Pennsylvania. His parentage and exact place of birth are unknown. By 1809, John Donihoo had settled in Rockbridge County, Virginia, where he was a member of the Falling Spring Presbyterian Church. In 1811, John married Martha M. Walker, daughter of Joseph Culton Walker and Jane Moore. John purchased the 725 acres of his father-in-law’s land on the Bent of the Buffalo (Creek) 9 miles south-west of Lexington, Virginia. It is believed that John owned a manufacturing business, a forge and/or cement works, which he ran with slave labor. He underwent a complete change of conviction regarding slavery, becoming an Abolitionist, and in May of 1835, he and his family left Rockbridge County for St. Clair County, Michigan Territory. He bought 187 acres on Recor’s Point on the St. Clair River border with Canada, where his now-freed slaves found sanctuary. His home in Michigan was a last stop on the Underground Railroad, by which escaped slaves found refuge in Canada. He is buried in Hillside Cemetery, St. Clair, Michigan, in an unmarked grave. Today there is an Underground Railroad Memorial marker on the Donihoo gravesite in memory of John and Martha, placed by the St. Clair (Michigan) Historical Commission: "John and Martha Walker Donihoo, from Lexington, Virginia, 1835. They freed their slaves and assisted others to freedom from their St. Clair River home."