 Canada <unk> Lines formed in 1913 from many previous companies that plied the waters of the St. Clair River . One of these companies was Northwest Transportation Company of Sarnia , which was founded in 1870 . By 20 April 1914 , when the residents passed Act to <unk> the City of Sarnia , the population had grown to 10 @,@ 985 in six wards . Sarnia officially became a city as of 7 May 1914 . 
