Personal records documenting the careers of Alexander Peter Cockburn and his children, Jean Elizabeth Munro, Harriet Macmillan Cockburn, James Roy Cockburn, Cecilia Catherine Cockburn, and Mary Barnfield. The records include diaries, certificates, legal documents, course notes and term papers, lecture notes, notes, medical case books, addresses, publications, blueprints, design drawings, photographs, lantern slides, sketches, trench and other military maps (First World War), press clippings and medals. The most extensive series record the activities of Alexander Peter Cockburn as president of the Muskoka and Nipissing Navigation Company; Harriet Cockburn as a medical doctor, especially relating to her service in Serbia during the First World War; Jean Munro's career as an artist in France; and Roy Cockburn's career as professor of engineering drawing in the Faculty of Applied Science and Engineering, and his military service in the First World War with the Royal Engineers in France and with the Egyptian Expeditionary Force under General Allenby in Palestine.
Photographs include Cockburn family members at and near Muskoka and at Moose Factory, Ontario; James Roy Cockburn with the Canadian Officers Training Corps, University of Toronto Contingent, and on his First World War military service in the Middle East. Taken by Charles W. Willey; Farmer Bros.; Park Bros.; Topley Photography; Notman & Fraser; F.W. Micklethwaite; Swaine Photography; C. Raad, Jerusalem.