Correspondence and notes of George C. Mahon of Detroit and Framingham (Mass.) mainly concerning the history of the family of Mahon of Co. Galway and Co. Clare, but including a correspondence between Mahon and John Martin on Irish Political and Religious questions, also letters from John D'Alton, John O'Mahony, Brian O'Looney and T.G.S. Mahon, Corbally, Ennis, c. 1830-1890.