James McMahon was written about in the Commemorative Biographical Record of the Counties of Huron and Lorain, Ohio, pages 297 and 298.

James married Bridget Perry in 1866 and had eight children: Rosa J. (Brady), James John, Mary Belle (Lynott), Susan Helen (Lepley), Agnes (Kuta), Edward Perry, Jewell (Julia) (Bumb) and Catherine Isabelle (Meredith).