Industrial unions were created by American and Canadian craft workers whose goals were to share revenues, create a more united front, increase information networks and secure standard work conditions across North America. Employers in Canada used the American connection to denounce Canada's affiliates. However, even the federal government was forced to acknowledge in a 1903 Royal Commission that these unions were making an important contribution to the workers' lives.

At the beginning of the twentieth century, the Quebec labour movement, particularly in Montreal, which was Canada's industrial centre, was dominated by international unions. They recruited their members from among the construction and transport workers, employees in the metal, print and garment industries, and skilled labourers in the manufacturing trades. Such unions were the instigators of most of the major strikes.