When Mary A. Pendleton was born on 19 December 1838, in Edmeston, Edmeston, Otsego, New York, United States, her father, Oliver Pendleton, was 35 and her mother, Mary Dennison Southworth, was 35. She married William Sharpless Jackson on 22 May 1860. They were the parents of at least 1 son. She lived in Wabasha, Wabasha, Minnesota, United States in 1870. She died on 22 July 1879, at the age of 40.