[1][2] Micklethwaite specialized in outside views and landscapes, as well as architectural and commercial photography, and he was one of Toronto's best known photographers.

[1] His family mpved to Ireland in the 1850s, where his father, William Barton Micklethwaite, practiced photography in Newry, County Down.

After working for three years as a proof reader for The Mail newspaper, he opened a commercial photography business at 22 Queen Street West in 1878.

[1] Micklethwaite also took up residence in Port Sandfield each summertime, and he took thousands of photographs of the Muskoka lakes area and wealthy cottagers.

[3] In addition to his private clients, Micklethwaite was also commissioned by the Engineer's Department of the City of Toronto government from approximately 1891 to 1895 to take photographs of public works and their construction.