Canadian spelling conventions can be partly explained by Canada's trade history. For instance, the British spelling of the word cheque probably relates to Canada's once-important ties to British financial institutions.[citation needed] Canada's automobile industry, on the other hand, has been dominated by American firms from its inception, explaining why Canadians use the American spelling of tire (hence, "Canadian Tire") and American terminology for automobiles and their parts (for example, truck instead of lorry, gasoline instead of petrol, trunk instead of boot).
Canada's political history has also had an influence on Canadian spelling. Canada's first prime minister, John A. Macdonald, once advised the Governor General of Canada to issue an order-in-council directing that government papers be written in the British style.
A contemporary reference for formal Canadian spelling is the spelling used for Hansard transcripts of the Parliament of Canada (see The Canadian Style in Further reading below). Many Canadian editors, though, use the Canadian Oxford Dictionary, often along with the chapter on spelling in Editing Canadian English, and, where necessary (depending on context), one or more other references. (See Further reading below.)
Throughout part of the 20th century, some Canadian newspapers adopted American spellings, for example, color as opposed to the British-based colour. Some of the most substantial historical spelling data can be found in Dollinger (2010) and Grue (2013). The use of such spellings was the long-standing practice of the Canadian Press perhaps since that news agency's inception, but visibly the norm prior to World War II. The practice of dropping the letter u in such words was also considered a labour-saving technique during the early days of printing in which movable type was set manually. Canadian newspapers also received much of their international content from American press agencies, therefore it was much easier for editorial staff to leave the spellings from the wire services as provided.
In the 1990s, Canadian newspapers began to adopt the British spelling variants such as -our endings, notably with "The Globe and Mail" changing its spelling policy in October 1990. Other Canadian newspapers adopted similar changes later that decade, such as the Southam newspaper chain's conversion in September 1998. "The Toronto Star" adopted this new spelling policy in September 1997 after that publication's ombudsman discounted the issue earlier in 1997. "The Star" had always avoided using recognized Canadian spelling, citing the Gage Canadian Dictionary in their defence. Controversy around this issue was frequent. When the Gage Dictionary finally adopted standard Canadian spelling, the Star followed suit. Some publishers, e.g. Maclean's, continue to prefer American spellings.