Mary Harrison was born on September 3, 1853 in the town of St. Marys. She was the second of five children born to Milner Harrison and Catherine Howard.

Mary’s grandfather, Thomas Harrison, was a trader and seafarer who traded goods to Russia during the early nineteenth century. In 1820, the family made the decision to emigrate to Canada and settle in what was then London Township.

Mary’s father, Milner Harrison, was born near York, England about 1816. Following in his father’s footsteps Milner was an affable, energetic and entrepreneurial young man. In 1842, he married twenty-two year old Catherine Howard who was born on July 3, 1822 the daughter of Thomas Whitfield Howard and Mary Goulding. The Howard family was purportedly related to Colonel Thomas Talbot who founded the Talbot settlement on Lake Erie. Catherine’s father had come to Canada in charge of a survey party and decided to remain and settle in the country.

Milner and Catherine moved to St. Marys about 1844 and established a general store on Queen Street. Along with other business savvy merchants such as Timothy Eaton, Milner was both successful and prosperous to the extent that he retired in his mid-forties but continued to invest and promote the development of the town.

On her twentieth birthday Mary Harrison wed John Hugh Mathieson on September 3, 1873.
John was born in West Zorra Township, Oxford County on March 27, 1844. He was the son of John Mathieson and Jane Middleton who farmed in the county. John was a Holmes gold medalist graduate from the Medical Faculty of McGill University in 1871 in the same class as Sir William Osler known as the father of modern medicine. John came to St. Marys shortly thereafter and established what would become a large and successful practice in partnership with Mary’s older brother Dr. David Howard Harrison. 

David was a witness to Mary and John’s marriage. In 1882, David relocated to Manitoba where he became a substantial landholder. He also became actively involved in politics and was elected to the provincial legislature as a Liberal-Conservative in 1883. He was subsequently appointed Minister of Agriculture, Statistics and Health by Premier John Norquay. When Norquay was forced to resign in 1887, David Harrison became the sixth premier of Manitoba. However, his term as premier was short lived because he was unable to form a coalition government and was forced to step down in 1888.

About eleven months after their marriage Mary purchased the newly built house at 109 Wellington Street North, presumably with an endowment from her father. Following her father’s death in 1887, Mary’s mother, Catherine, came to live with the young couple until her death in 1892.

The house, called “The Maples,” became a centre for political, social, literary and artistic gatherings in the town as through the years John served on St. Mary’s Council, the School Board and the Library Board. As a councillor he was instrumental in getting the St. Marys town hall built by encouraging his colleagues to consider that “We are not building a hall or market for now, but for years and generations to come.” resulting in the remarkable structure we see today.

On October 13, 1884 Mary gave birth to Donald Milner Mathieson the couple’s only child. He graduated as a Civil Engineer from the Royal Military College in 1905. In 1907 he married Constance Elmhorst Lightbound at Saint Gabriel Presbyterian Church in Montreal. The young couple moved to British Columbia. When World War I was declared in August 1914, Donald was likely recalled to active service. His attestation papers show that he re-enlisted on September 24, 1914 at the improvised military base at Valcartier, Quebec established by Defence Minister Sam Hughes.  Following the war Donald had a successful business career serving as director of a number of companies and travelling throughout the world. He died in Vancouver on December 1, 1952.

Mary and John continued to be popular and progressive members of St. Marys society as exemplified by an 1897 newspaper article in which Mary extended an invitation to townsfolk to visit her house to view the workings of one of the first dishwashing machines in Canada, which according to the article “will be a boon to ladies by eliminating the drudgery of washing dishes.”

John Mathieson died suddenly on May 10, 1914. Mary continued to live in her beloved house until her death on January 24, 1919. She is buried alongside her husband in St. Marys cemetery.