wikipedia

By the time the United Kingdom joined the European Economic Community in 1973, the idea of the UK as an alternative to the USA as Canada's largest market was no longer viable. Canada and the United States signed the Free Trade Agreement in 1988 (which was expanded into NAFTA by the addition of Mexico in 1994). Since that time the United States has dominated Canadian trade by an overwhelming degree. After the Wars, trade with Asia began to expand, especially China. After the opening of Canada–People's Republic of China relations in 1970, trade with China has expanded rapidly.