Dominion Police
The Dominion Police Force was the federal police force of Canada between 1868 and 1920, and was one of the predecessors of the Royal Canadian Mounted Police. It was the first federal police force in Canada, formed the year following the Canadian Confederation to enforce federal laws and perform policing duties for the Federal Government of Canada. On 1 February 1920, the Dominion Police was merged with the North-West Mounted Police to form the Royal Canadian Mounted Police as the new federal police force of Canada.
RCMP Security Service
In 1950, the Royal Canadian Mounted Police's Special Branch was formally established to conduct its counterintelligence operations. Prior to that, the branch was a component of the RCMP's Criminal Investigation Branch, where political security operations and criminal investigations were not distinct before 1936. The Mounties carried out extensive security service work since the force was reconstituted in 1920, when it merged with the Dominion Police and became the federal police agency solely responsible for national security. Between the wars, this work was overwhelmingly directed at the Communist Party and labour and the left more generally.