Mary S. Clarkson was born on February 10, 1794, in Woodford County, Kentucky. Her mother, Sarah Watkins Field, was murdered in 1799, and her father was executed for the crime shortly thereafter. Henry Clay acted as his defense attorney and the case, decided on circumstantial evidence, remained contentious even after Field's execution. Following the death of Mary's parents, her aunt, Elizabeth McClanahan, of Bourbon County, Kentucky, raised Mary and her four sisters. Mary later married David Clarkson. After his death, she lived with her sister, Sallie Moseley, and Sallie's husband, Thomas. Thomas Moseley, Jr. (1792-1858) served as a subagent on the Wyandot Indian Reserve in what is now eastern Kansas and later headed the Kansas Agency. Mary S. Clarkson died on April 18, 1871, in St. Louis, Missouri.