When Susan Virginia Knapp was born on 22 July 1867, in Union District, Mason, West Virginia, United States, her father, Moses Knapp, was 25 and her mother, Samantha Smith, was 22. She married Richard Beattie Cain on 17 November 1888, in Union District, Mason, West Virginia, United States. They were the parents of at least 3 sons and 5 daughters. She died on 22 February 1949, in Hartville, Stark, Ohio, United States, at the age of 81, and was buried in Obetz Cemetery, Obetz, Franklin, Ohio, United States.