At its first convention in Regina, Saskatchewan it selected James Woodsworth (an Independent Labor Party MP since 1921) as its leader and adopted the Regina Manifesto as its policy program. The manifesto outlined a number of goals, including:
In its first election in 1935, the CCF elected 7 MPs to the House of Commons, and the following election in 1940 elected 8 members. But the party was divided with the outbreak of World War II as Woodsworth was an uncompromising pacifist and this upset many supporters of the Canadian war effort. A new leader, Major Coldwell, was elected and threw the party's support behind the war. The party won a critical York South by-election in February 1942, and in the process prevented the Conservative leader, former Prime Minister Arthur Meighen, from entering the House of Commons. In the next federal election the CCF returned 28 MPs and won 15.6% of the vote.
However, the party was to have its greatest success in provincial politics. In 1943 it became the official opposition in Ontario, and in 1944 it formed the first socialist government in North America in Saskatchewan with Tommy Douglas as premier. Douglas introduced universal healthcare to Saskatchewan, a policy that was soon adopted by other provinces and implemented nationally by the Liberals under Lester B. Pearson.
Federally, during the Cold War period the CCF was accused of having communist, dictatorial leanings. To quash these accusations the Regina Manifesto was replaced by a more moderate document, the Winnipeg Declaration, in 1956. Nevertheless, the party did poorly in the 1958 federal election and elected only eight MPs.
After much discussion, the CCF and the Canadian Labour Congress decided to join forces to create a new political party, which could make democratic socialism more popular with Canadian voters. In 1961 the CCF became the New Democratic Party.