The Co-operative Commonwealth Federation was organized in Calgary, Alberta as a political coalition of progressive, socialist and labour groups for the purpose of initiating reforms in the federal government to alleviate the economic and human suffering resulting from the Great Depression. Formed from a number of western farmers' organizations, by a few academics, and by a ginger group of federal politicians supportive of both farmer and trade union organizations, the CCF adopted the Regina Manifesto that set out its goals. Led by J. S. Woodsworth, the Federation achieved a moderate level of electoral success in federal politics, but the main source of its victories at the provincial level came in Alberta, Saskatchewan and Manitoba.

Other provinces proved far less accepting of the CCF message. As the party expanded eastward, it experienced less success at the provincial and federal levels. After the Second World War, the Federation, undermined by internal dissent and the boom of the post-war economy, was rendered near obsolete. The CCF's main importance in Canadian politics was the groundbreaking introduction of the social left to Canadians and, in 1961, the birth of the New Democratic Party at a convention of CCF and Canadian Labour Congress members.