Personal
In 1901, James Dunn was married to Gertrude Paterson Price, the daughter of a prosperous Quebec City lumber dealer. They had five children before divorcing in 1926:
Mona Dunn (c. 1902–1928). Widely described as 'the most beautiful girl in England' she became at 17 when he met her in Paris in 1919 the mistress of Lord Birkenhead, who was then Lord Chancellor in the Coalition Cabinet of David Lloyd George. She married in 1925 Edmund Tattersall, a war hero of the 5th Dragoon Guards with whom she had in May 1927 a daughter, Monica. Her portrait by William Orpen hangs in the Beaverbrook Art Gallery, Fredericton, New Brunswick, Canada, and may be viewed on their web-site. Her early death on 19 December 1928 from peritonitis was a crushing blow to her father. It became the subject of an occasional poem by Shane Leslie, which was published by the Ashendene Press.
Sir Philip Gordon Dunn, 2nd Baronet Dunn (1905–1976), who was father of two daughters: the author Nell Dunn, and Serena Dunn, later Lady Rothschild.
Kathleen Mabel Dunn (1907–1969) - she married stockbroker Peter Higgins but the couple were divorced. She married in 1947 Colonel Sir Robert Philip Wyndham Adeane, O.B.E. (1905–79), kt., of Babraham Hall.
Joan Molesworth Dunn (1908–1982) who married 1928 (and was divorced 1 November 1929 by) Hubert Duggan, an MP, and stepson of Lord Curzon. Upon her divorce she lost custody of an infant child born on 5 August 1929. She next married her lover Anthony Jenkinson, who subsequently committed suicide in October 1935. She married last in 1943, Charles Dutton, 7th Baron Sherborne.
Brigid Leila Dunn (1919–1991)
Following the divorce from his first wife in 1926, Sir James Dunn married Irene Clarice Richards, the former wife of Francis Archibald Kelhead Douglas, 11th Marquess of Queensberry. The 1928 death of his daughter Mona Dunn from his first marriage sent him into a state of depression and for a time he thought about cutting back on his business activities and returning home to his native New Brunswick. However, in 1929, his new wife gave birth to a daughter, Anne, who lifted his spirits a great deal. Anne Dunn grew up to be an artist, studying under Henry Moore and in Paris, France with Fernand Léger and at the Académie Julian. Nevertheless, Dunn and his second wife divorced in 1942 following which he married his long-time personal secretary, Marcia Anastasia Christoforides. Thirty-six years his junior, "Christofor" as she was nicknamed, was very bright, intensely loyal, and a devoted partner. James Dunn would seek her input on most every business matter for the rest of his life.
Although a workaholic, enjoyed luxury and maintained an active social life. He was one of the first businessman to acquire a Douglas DC-3 as a private business aircraft, in which he traveled frequently between his homes in Europe and Canada. He kept a vast wine cellar from the vineyards of France and frequented New York City, especially Broadway where he was a friend of television host Ed Sullivan.
It was for his service in the Great War that Dunn was knighted in the 1921 New Year's List of Honours. Dunn functioned as a sort of emissary for two Prime Ministers. He first responded when Asquith asked him (and members of the Asquith family) in the autumn of 1914 to write a report on the Army hospital service behind the lines in France. Next, he negotiated with Jacob Borreson an agreement that all of the nickel mined by the Kristiansand Nickel Company of Norway would be sent to Canada for smelting and refining. The British government obtained a virtual blockade on the supply of nickel to Germany, which was forced to purchase nickel from afar (with all the risk entailed by a distant supply) at inflated "spot" prices. Lloyd George requested a situation report from Dunn on the disrupted supply of foodstuffs from Norway, Sweden and Denmark; Dunn's plans for increasing the supply were sound and worked admirably in practice.
In 1949, Dunn was made a King's Counsel in Quebec by Maurice Duplessis. He was a made a member of the bar in five provinces. On 15 August 1950, he was made a Freeman of the City of Bathurst, and in November 1954 the same honour was bestowed by St. Andrews, New Brunswick. The University of New Brunswick, Dalhousie University, St. Francis Xavier University, Laval University and Queen's University all granted him honorary degrees. Sault Sainte Marie awarded him the Freedom of the City.
In January 1956 at the age of 81, after a heart ailment of less than a week Dunn died at his home in St. Andrews, New Brunswick. In commemoration of his birthday, in the same year, Lady Dunn privately published The Ballad of a Bathurst Boy: 1874-1956, a celebration of her late husband's life in verse. Printed by the University of New Brunswick Press in Fredericton, NB, it was sent to friends and family of Dunn. His widow sold the 10,000 acre camp he had acquired near his birthplace the next year. One source places this parcel on Dunn Road near Allardville, New Brunswick.
Lord Beaverbrook (Max Aitken) published in 1961 a detailed biography of his late friend, titled Courage: The Story of Sir James Dunn. The most complete telling of Dunn's life and business career is available in Duncan McDowall's, Steel at the Sault: Francis H. Clergue, Sir James Dunn and the Algoma Steel Corporation 1901-1956 (Toronto:University of Toronto Press, hb 1984 & pb 1988).
At the time of his death, Dunn was president of Algoma Ore Properties Ltd, Cannelton Coal and Coke Company, Fiborn Limestone Company, and Canadian Furnace Company.