Church ministry Cowan was ordained by the Chatham Presbytery of the
Presbyterian Church in Canada on August 17, 1897. a minister in charge of St. Paul's Presbyterian Church in Harwhich Township,
Kent County, Ontario, Bethel Presbyterian Church, and The Ridge Presbyterian Church from 1905 to 1913, in Haynes Ave. Church in
St. Catharines from 1914 to 1916, Chalmer's Presbyterian Church in
Toronto from 1919 to 1921, and in High Park Presbyterian Church in 1922. The book was recently republished on April 9, 2012, as
Ontario and the Detroit Frontier 1701–1814. Another book on
Chatham, Ontario including Kent County and Lambton County includes information on the Underground Railway as well as the early history of the communities in the area. The book was created as part of the Canadian Achievement in the Province of Ontario but currently only exists in a galley proof in The Chatham Public Library. Another of his histories was
Gold and Silver Jubilee, Sault Ste. Marie, Canada, incorporated a town, 1887, a city, 1912 detailing the history of
Sault Ste. Marie, that includes illustration of its port and map of the city.
Mer Douce was an historical magazine later published in book form, that includes articles of history and life in the Georgian Bay, Manitoulin Island, Parry Sound and other communities of Ontario. It is considered an important historical reference in the region. He also wrote a fictional book entitled
La Cloche. The Story of Hector MacLeod and His Misadventures in the Georgian Bay and the La Cloche Districts is an adventure tale of a United Loyal Empire Loyalist set in
Georgian Bay, Ontario of what was then
Upper Canada. The book was recently republished on April 3, 2014, under the title
The Misadventures of Hector MacLeod: In the Georgian Bay and the La Cloche Districts. Cowan also served as the managing editor of Algonquin Historical Society of Canada. Hugh Cowan also published a book reflecting the progress of Christianity over his years of ministry and some of the major questions he encountered. It was published in 1937 and was entitled
The Great Drama of Human Life. The book was recently republished on January 30, 2014, under its original title. ==Death==