Margaret Blair (maiden name: Steele) was born around 1800 in Pennsylvania. She married David Blair around 1821, and they had at least five children: Samuel, born in 1821; Elizabeth, born around 1829; Margaret, born around 1832; John, born in 1833; and Sarah, born around 1836. They lived in Indiana County, and her husband worked as a Presbyterian minister. They owned $3,000 of real estate in 1850. A decade later, they owned $9,000 of real estate and $500 of personal property. Margaret died in Indiana County on April 6, 1865.