In 1980 Mark was appointed Secretary of State for External Affairs and in 1982, Minister of Justice and Attorney General of Canada. In 1984 he was appointed Judge of the Federal Court of Appeal, where he served until his death in 1998.

In 1995 Mark was awarded the Tamopolsky Medal for Human Rights by the Canadian Section of the International Commission of J urists and received honorary doctorates of law from: University of Prince Edward Island (1971), St. Thomas University (1981), the Law Society of Upper Canada (1983), University of Windsor (1983), York University (1996).

On June 17‘“, 1961, Mark married Maryellen Symons and they became the parents of three children: Ellen Frances MacGuigan Symons, Ottawa, Ont. - business owner, writer and yoga teacher ', Mark Rudolph MacGuigan 111, Ottawa, Ont, Chief Technician, School of Architecture, Carleton University; Thomas James MacGuigan, Windsor, Ont. - free lance musician - father of Tashina Naomi MacGuigan (1989), Tecumseh Raven MacGuigan (1995).

Following a divorce from Maryellen Symons, Mark married Patricia Dougherty and became step-father to : Sarah Elizabeth Maye (Beth), Oklahoma City, Oklahoma - writer, Artist-in-residence, Oklahoma Arts Council - mother of Jessica Anne Maye (1995), Jonathan Rowan Maye (1997), Abigail Grace Maye(2000); James McKee Robinson IV (Buddy), San Antonio, Texas- attorney, SBC Communications Inc.- father of Elizabeth Arthur Robinson (2000).

Mark died January 12*, 1998

Mark was involved in writing and the publication of numerous books and articles. His preferred pursuits were reading, music ( he played the piano as a young man and had a life-long love of concerts and recordings), travel( especially to France), good food, good wine, and talking to people and finding out about their interests and lives. He was enormously proud of his children and loved his wife, Patty, dearly.

Mark’s daughter, Ellen, says: “His time at St.Dunstan’s was the foundation of all his other educational experiences, he also made life- long friends whom he cherished. This reunion is exactly the kind of event my father would have relished, and he would have been delighted to share stories and recollections with his former classmates”.